Clean and trim all of the vegetables, and cut them into 1- to 2-inch pieces. Try to keep all of the pieces the same size so that they'll cook evenly.
Heat a tablespoon or two of olive oil in a large skillet. Cook the tofu cubes until they form a golden-brown crust.
Heat a tablespoon of olive oil in a wok, and saute the vegetables. Start with the more dense foods like carrots, broccoli, and cauliflower. When those just begin to soften, add the onions and red pepper. When the onions become translucent, add the green onions, mushrooms, and tofu to the wok and cook another minute or two.
Combine all ingredients for the sauce. Blend well and pour over the stir fry. Toss to coat.