Beef and Onion Stir-Fry with Fresh Tomato Salsa

By AislePrompt Editorial · Published 2026-04-17 · Updated 2026-04-17

How this recipe was made — this recipe was drafted by AislePrompt's AI-assisted pipeline from technique templates and USDA-sourced nutrition data, and published by AislePrompt Editorial — see how AislePrompt recipes are developed and reviewed.

Juicy flank steak strips stir-fried with caramelized onions and bell peppers, served with a bright, zesty tomato-cilantro salsa. This Fusion-inspired beef recipe, ready in about 45 minutes, pairs flank steak, soy sauce, cornstarch for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 380 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 25 min Cook: 20 min Serves 4 Fusion cuisine 380 cal/serving

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Ingredients

1.5 lbs, thinly sliced against the grain flank steak
3 tbsp, divided soy sauce
1 tbsp cornstarch
2 tbsp, divided vegetable oil
2 large, thinly sliced onion
1, thinly sliced red bell pepper
1, thinly sliced green bell pepper
3 cloves, minced garlic
1, diced tomato
2 tbsp, chopped fresh cilantro
1 tbsp lime juice

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Instructions

Step 1: In a bowl, toss 1.5 lbs flank steak with 2 tbsp soy sauce and 1 tbsp cornstarch. Let sit 15 minutes.
Step 2: Heat 1 tbsp vegetable oil in a skillet over high heat. Add beef and stir-fry 2-3 minutes until browned but not fully cooked. Remove and set aside.
Step 3: Add remaining 1 tbsp vegetable oil to skillet. Sauté 2 large onions (thinly sliced), 1 red bell pepper (thinly sliced), 1 green bell pepper (thinly sliced), and 3 garlic cloves (minced) for 5-7 minutes until onions are caramelized and peppers tender.
Step 4: Return beef to skillet, add remaining 1 tbsp soy sauce, and stir-fry 2-3 minutes until beef is cooked through. Mix 1 diced tomato, 2 tbsp fresh cilantro, and 1 tbsp lime juice for the salsa.
Step 5: Serve beef and vegetables hot with fresh tomato-cilantro salsa on the side.