Remove tofu from package and cut in half horizontally. Place each half on clean dish towels or paper towels and let stand, patting the tops and sides with towels. This should remove a fair amount of water.

In a medium bowl, combine rice vinegar, soy sauce, agave, sesame oil and red pepper flakes. Dice tofu into 1 inch cubes. Add tofu to marinade and allow to marinate at least 30 minutes, preferably two hours, turning occasionally. Remove tofu and reserve marinade. Stir one teaspoon of cornstarch into water to dissolve, add to marinade.

Heat one tablespoon canola oil in a large skillet or wok over medium high heat. Add tofu pieces and cook until light golden, about three minutes. Set tofu aside. Heat remaining oil and add mushrooms and carrots, cook three minutes, stirring occasionally. Add cabbage and peas, cook three minutes, stirring to wilt cabbage. Add garlic, ginger and scallions, cook one minute, stirring constantly. Return tofu to pan and pour in marinade and season with pepper. Cook about 30 more seconds to thicken sauce. Transfer to a serving bowl.