Step 1

Heat 1 1/2 tablespoons of the vegetable oil in a large pan over high heat. Place the steak in a medium sized bowl with the cornstarch and salt and pepper to taste. Toss gently to combine..

Step 2

Place the meat in a single layer in the pan. Cook for 2-3 minutes per side until golden brown. You may have to do this step in batches.

Step 3

Remove the steak from the pan. Cover with foil to keep warm.

Step 4

Pour the remaining vegetable oil into the pan. Add the onion and both types of bell peppers. Cook for 4-5 minutes or until vegetables are softened.

Step 5

Add the garlic to the pan; cook for an additional 30 seconds. Return the beef to the pan. Stir in the peanuts and chilies.

Step 6

While the meat and vegetables are cooking, make the sauce. Place all of the ingredients in a small bowl and whisk until combined.

Step 7

Add the sauce to the steak mixture and bring to a boil; cook for 1 minute, or until sauce is just thickened. Serve immediately.