Slice onions and chop garlic and let both sit for at least 5 minutes to bring out their nutritional benefits. Heat the olive oil in a wok or 10-12 inch stainless steel skillet. Stir fry the onion in olive oil for about 3 minutes over medium heat, stirring constantly. Add garlic, ginger, asparagus, peppers and continue to stir fry for another 2-3 minutes, stirring constantly. Add tofu, soy sauce and vinegar, turn heat to low and cover for about 5 minutes or until vegetables are fork tender, yet still crisp. Season with salt and pepper and sprinkle with sesame seeds. Makes 4 servings.