Preheat the oven to 425 degrees F.
Cut up all of the ingredients. Cut the tofu into cubes. Cut a head of cauliflower into florets. Slice up the onion and the bell peppers. Then cut up the pineapple into chunks.
Cook the rice according to package directions.
Place the tofu cubes on a lightly greased foil-covered baking sheet. Bake for 25 to 35 minutes.
Put the cauliflower on a lightly greased foil-covered baking sheet. Sprinkle with salt and roast for 20 to 30 minutes until cooked through.
While the cauliflower and tofu are baking, mix all of the sauce ingredients together in a small saucepan and heat over medium-low for 20 minutes, stirring occasionally. The mixture will reduce considerably and should be the consistency of barbecue sauce.
Heat a large nonstick skillet over medium heat. Add the vegetable oil and then the onion and saute for about 3 minutes, stirring occasionally. Then add the bell peppers and saute for another 5 minutes.
Then assemble the bowls with rice, roasted cauliflower, baked tofu, the onion/pepper mix, and fresh pineapple. Drizzle the sauce on top. Sprinkle with sesame seeds if desired.