|Wash the heads of bok choy well and trim the bottom. Cut the bottom, whitish part of the stalk into 1/2-inch slices. Set them aside and slice the green leaves thinly and place on a separate plate.Cut the tofu into slices or cubes.Combine the orange juice, soy sauce, agave, rice vinegar, sesame oil, and cornstarch in a small bowl.
Heat a large wok or deep skillet. Quickly spray with canola oil, if necessary, and add the bok choy stalks, carrot, broccoli florets, peppers, onions, and ginger. Cook for 2-3 minutes. Add snow peas, garlic, and mushrooms and continue to cook until mushrooms begin to soften, about 2 more minutes.
Stir in the bok choy greens, place the tofu on top, and cover tightly. Steam briefly until greens are wilted and bright green, about 1-2 minutes.
Stir the orange juice mixture, add it to the skillet, and bring to a boil. Simmer until slightly thickened, about 30 seconds. Serve with rice or other grain.