Sauteed Sirloin Tips With Bell Peppers And Onion

sirloin steak, cut into 1-inch pieces

Teriyaki or Soy sauce

packed light brown sugar

olive oil, plus additional for cooking

chopped Italian parsley or cilantro

garlic, minced

red pepper flakes

steak seasoning, divided [i.e. Mesquite/Montreal/Chicago/ Kansas City your preference]

red bell pepper, seeded and sliced

green bell pepper, seeded and sliced

large sweet onion, cut into thin wedges

Black pepper