This pork and onion stir-fry marries Chinese stir-fry technique with pantry sauces many American kitchens already have. Thin-sliced pork, sweet onions, and a tangy-savory glaze come together in under 30 minutes. It’s fast, deeply satisfying, and perfect over steamed rice or noodles.

Recipe at a Glance

• Serves: 3–4
• Active time: 20 minutes
• Total time: 30 minutes
• Core flavors: savory, slightly sweet, gently tangy
• Skill level: easy weeknight stir-fry

Why This Recipe Works

• Balanced sauce: Ketchup brings tomato umami, subtle sweetness, and acidity; Worcestershire adds depth. Soy sauce and a splash of dark soy round out salt and color.
• Restaurant-style tenderness: A brief “velveting” marinade (soy, wine, cornstarch, tiny pinch of baking soda) keeps pork silky even on high heat.
• Speed and minimal prep: Mostly onions and pork with a quick sauce. The wok does the heavy lifting.

AEO Quick Answers

What is pork and onion stir-fry?

Pork and onion stir-fry is a quick Chinese-style dish of thinly sliced pork seared hot with onions and a glossy sauce. This version uses soy sauce, ketchup, and Worcestershire for a savory-tangy glaze. It cooks in minutes, making it ideal for weeknights served over rice.

How do you tenderize pork for stir-fry?

Toss thinly sliced pork with light soy sauce, Shaoxing wine (or dry sherry), a pinch of baking soda, and cornstarch. Rest 10–15 minutes. The baking soda raises surface pH to keep fibers tender, while cornstarch forms a protective coating for juicier results on high heat.

Can I make this without a wok?

Yes. Use a large stainless steel or carbon steel skillet. Heat until very hot, add a thin film of oil, and sear in batches to prevent steaming. The technique is the same: brown the pork, cook onions, then combine with sauce until glossy and thickened.

What does ketchup add to stir-fry sauce?

Ketchup brings tomato richness, gentle sweetness, and vinegar tang, creating an instant sweet-and-savory profile. It pairs well with Worcestershire (umami, anchovy depth) and soy sauce (salt and savoriness), producing a balanced, family-friendly glaze for pork and onions.

Ingredients

Pork and Marinade

• 1 lb (450 g) pork shoulder/butt, thinly sliced against the grain (loin or tenderloin also works)
• 1 tbsp light soy sauce
• 1 tbsp Shaoxing wine (or dry sherry)
• 1 tsp sugar
• 1/4 tsp baking soda (don’t exceed)
• 1 tbsp cornstarch
• 1 tsp neutral oil (canola, peanut, or avocado)
• 1/8 tsp white pepper (optional)

Stir-Fry

• 2 medium yellow onions, halved and sliced 1/3-inch thick
• 3 cloves garlic, thinly sliced
• 2 scallions, cut into 1-inch pieces (greens and whites separated)
• 2–3 tbsp neutral oil for stir-frying

Sweet-Savory Sauce

• 3 tbsp ketchup
• 1 tbsp Worcestershire sauce
• 1 tbsp light soy sauce
• 1 tsp dark soy sauce (for color; optional)
• 1 tbsp oyster sauce (depth; optional but recommended)
• 1 tsp rice vinegar (adjust to taste)
• 1/2 cup (120 ml) low-sodium chicken stock or water
• 2 tsp cornstarch
• 1/2 tsp toasted sesame oil

To serve: steamed rice or stir-fried noodles

Step-by-Step Instructions

1. Slice the pork: For ultra-thin slices, partially freeze the pork 30 minutes until firm around the edges. Slice against the grain into 1/8–1/4 inch pieces.
2. Marinate: In a bowl, combine soy sauce, Shaoxing wine, sugar, baking soda, white pepper, and pork. Mix well, then add cornstarch and oil. Toss to coat. Rest 10–15 minutes while you prep the other ingredients.
3. Make the sauce: Whisk ketchup, Worcestershire, light soy, dark soy, oyster sauce, rice vinegar, stock/water, cornstarch, and sesame oil until smooth. Set aside.
4. Preheat the wok/skillet: Heat over high until just smoking. Add 1 tbsp oil, swirl to coat.
5. Sear the pork in batches: Lay pork in a single layer. Sear 60–90 seconds per side until just browned and mostly cooked. Transfer to a plate. Repeat with remaining pork, adding oil as needed.
6. Aromatics and onions: Add 1 tbsp oil. Stir-fry garlic and scallion whites 10–15 seconds until fragrant. Add onions and a pinch of salt. Stir-fry 2–3 minutes until edges char and centers turn translucent but still crisp-tender. If needed, splash 1–2 tbsp water to steam through.
7. Combine: Return pork and any juices to the wok. Stir the sauce (cornstarch settles) and pour it in. Toss 30–60 seconds until the sauce bubbles and turns glossy, coating pork and onions.
8. Finish: Add scallion greens, toss, and remove from heat. Taste and adjust with a touch of vinegar for brightness or a pinch of sugar for balance.
9. Serve hot over rice or noodles.

Expert Cooking Tips

• Choose the right cut: Pork shoulder offers juiciness and flavor; loin and tenderloin are leaner and cook very fast—avoid overcooking.
• Velveting know-how: Use only a small pinch of baking soda and keep marination under 20 minutes to prevent off flavors.
• Onion control: Slice a bit thicker for crunch or thinner for jammy sweetness. Char the edges briefly for smoky depth.
• Heat management: Cook the pork in batches to keep the pan searing-hot. Crowding leads to steaming and pale meat.
• Sauce balance: If your ketchup is very sweet, reduce the sugar in the marinade or add a splash more vinegar at the end.
• Glossy finish: Cornstarch needs a brief boil to activate. Let the sauce bubble before you kill the heat.
• Rice pairing: Use hot, freshly cooked jasmine rice to catch all the savory-sweet sauce.

Common Mistakes to Avoid

• Overcrowding the pan: Leads to steaming and tough meat. Sear in 2–3 quick batches.
• Too much baking soda: Can cause a soapy taste. Measure carefully.
• Undercooking the sauce: If it doesn’t bubble, it won’t thicken properly.
• Overcooking onions: You want tender-crisp with light char, not mush.
• Skipping the rest after slicing: A brief marinade makes a noticeable difference in texture and flavor.

Best Tools for Stir-Fry Success

Great tools make fast cooking easier. If you don’t have these, any sturdy skillet and spatula will do.

• 14-inch carbon steel wok (round-bottom or flat-bottom)
• Metal wok spatula or fish spatula (for flipping without tearing meat)
• Long cooking chopsticks (for clean, precise tossing)
• Sharp chef’s knife or slicer for thin, even cuts
• Digital kitchen scale (for consistent sauce ratios)

Affiliate note: For shopping, look for quality carbon steel woks, metal spatulas, and sharp chef’s knives on Amazon or your favorite cookware store. Use a seasoned carbon steel wok for best sear and easy release.

Variations and Substitutions

• Spicy version: Add 1–2 tsp chili crisp or a slit fresh chili with the aromatics.
• No-ketchup alternative: 1 tbsp tomato paste + 1 tsp sugar + 1–2 tsp vinegar + 2–3 tbsp water to mimic ketchup’s profile.
• Gluten-free: Use gluten-free tamari and a certified gluten-free Worcestershire. Check your oyster sauce or swap with fish sauce to taste.
• Extra veg: Add bell peppers, celery, snow peas, or mushrooms after onions start to soften; keep total veg to 2–3 cups so the pan stays hot.
• Protein swap: Try chicken thigh, thin-sliced beef, or firm tofu (press well and dust lightly with cornstarch before searing).
• Ginger-forward: Add 1 tbsp julienned ginger with the garlic for a brighter, shogayaki-inspired profile.

Serving and Make-Ahead

• Serve with: Steamed jasmine rice, egg-fried rice, or plain lo mein.
• Meal prep: Slice pork and onions and mix the sauce up to 24 hours ahead. Stir-fry just before serving.
• Leftovers: Refrigerate up to 3 days. Reheat in a hot skillet with a spoon of water to loosen the sauce.

FAQ

What’s the best cut of pork for stir-frying with onions?

Pork shoulder (butt) is ideal: it’s flavorful, marbles nicely, and stays juicy. Lean cuts like loin or tenderloin work, but you must slice thinly and cook fast to avoid dryness. If using very lean cuts, reduce cook time slightly and don’t over-batch the pan.

Is ketchup “authentic” in Chinese cooking?

Ketchup-based sauces appear in Chinese diaspora and Hong Kong–style cooking, where sweet-tangy tomato notes complement quick-seared meats. While not traditional in every regional cuisine, it’s a well-loved, pragmatic pantry shortcut that tastes great and mirrors the sweet-sour balance found in many classic sauces.

How do I slice the pork thinly and evenly?

Partially freeze the pork for about 30 minutes until the surface is firm but not rock solid. Use a sharp chef’s knife and slice against the grain into 1/8–1/4 inch pieces. Keep your non-cutting hand’s fingers tucked and use smooth, even strokes for clean slices.

Can I cook this in a nonstick pan?

Yes, but preheat thoroughly and avoid very high heat to protect the coating. Sear in smaller batches to maintain sizzle. Nonstick won’t brown as aggressively as carbon steel or stainless, but it’s perfectly serviceable for weeknight cooking.

How do I keep pork tender without over-marinating?

Use a light velvet: soy, wine, a pinch of baking soda, cornstarch, and oil for just 10–15 minutes. Don’t exceed 1/4 teaspoon baking soda per pound of meat, and avoid marinating longer than 20 minutes to prevent off flavors or a spongy texture.

What if my sauce is too sour or too sweet?

If too sour, add a pinch of sugar or a small splash of stock and simmer. If too sweet, balance with a few drops of rice vinegar or an extra dash of soy. Always let the sauce bubble to integrate flavors before final tasting.

Can I double the recipe?

Yes—just sear the pork and cook onions in multiple batches to keep high heat. Combine everything at the end and add sauce in two pours, letting it come to a boil each time so the cornstarch activates and the glaze stays glossy.

Affiliate-Friendly Gear Notes

Looking to upgrade your stir-fry setup? Consider a 14-inch carbon steel wok, a metal wok spatula, and a razor-sharp 8-inch chef’s knife. If you prefer a skillet, a 12-inch stainless steel pan with a heavy bottom holds heat well for searing. Search Amazon for reputable brands with strong user reviews.

Conclusion

This pork and onion stir-fry is proof that technique beats complexity. A smart velvet, a balanced ketchup–Worcestershire glaze, and hot, fast cooking yield a takeout-caliber dinner in minutes. Keep it simple, cook it hot, and serve it immediately for the best texture and flavor.

Related recipes to link next: Easy Beef and Pepper Stir-Fry, 10-Minute Garlic Green Beans, The Ultimate Guide to Stir-Fry Sauces.