Slice flank steak across the grain into very thin 2 1/2-inch long strips.
Combine beef broth, cornstarch, sherry and chili sauce in a small bowl and set aside.
Heat a large wok or skillet over medium-high heat. Add half of the peanut oil and quickly stir-fry garlic until fragrant and golden, about 1 minute. Remove and discard garlic with a slotted spoon. Add flank steak and salt and cook until browned on both sides, about 4 minutes; remove to platter when done. Drain oil, wipe wok and reheat. Add remaining oil and stir-fry green bell peppers until almost tender, about 3 mintues. Add reserved sauce mixture and toss briskly for 1 minute or until sauce reduces and thickens. Add flank steak and cook until thoroughly heated. Serve immediately.
Servings: 4