Drain the tofu between paper towels (set a plate on top of tofu for about 15 mins to drain)
then cut into 1 inch chunks.
Whisk egg with 2 Tbs. water. In a separate bowl or a bag mix cornstarch with boullion if using.
Dip tofu chunks into egg mixture then coat with cornstarch mixture. Fry in hot oil until golden brown. You may need to do this in batches if your pan is not big enough. Drain the browned tofu on paper towels.
In a small amount of oil in a separate pan fry the onions, peppers, ginger and garlic for about 2 minutes at a medium heat. When garlic starts to brown add the broth, soy sauce, sugar, pepper flakes, vinegar and sherry if using.
Quickly whisk 1 Tbs of cornstarch with 2 Tbs of water and add this to the pan, stirring to thicken the sauce. As soon as the sauce begins to thicken remove from heat and add the tofu to the sauce. Garnish with sesame seeds.
Serve with cooked rice, steamed broccoli and a fortune cookie.