Combine the first five marinade ingredients. Add the sliced beef to a large re-sealable plastic bag, pour in ½ cup of marinade, and let sit for 30 minutes in fridge.

In a small bowl, whisk cornstarch and the rest of the marinade until smooth.

Drain and discard meat marinade. In a large nonstick skillet, stir-fry beef in oil for 2-3 minutes, then set aside.

Stir-fry sliced carrots and onion in skillet for 5 minutes. Add red pepper and peas; stir-fry 3-4 minutes longer.

Stir cornstarch mixture and add to the pan. Bring to a boil; cook and stir for 2 minutes or until thickened. Add beef and pineapple chunks; heat through.

Serve with brown rice.