Heat 2 tsp oil in large skillet over medium-high heat. Add beef and cook until browned on all sides, about 5 minutes. Transfer meat with its juices to a plate.
Heat remaining 2 tsp oil in same skillet over medium-high heat. Add peppers and onion and cook, stirring occasionally, 5 minutes. Add garlic and continue cooking until peppers are softened and onions are translucent, about 5 minutes more.
Return beef and juices to skillet and add broth, wine, soy sauce, and pepper. Bring to boil. Reduce heat and simmer until liquid has been reduced by half, about 5 minutes. Stir in dissolved cornstarch and cook until mixture thickens, about 2 minutes. Serve over rice.