Prepare peanut sauce by spraying cooking spray in a medium skillet set over medium-high heat. Sauté onions for about 5 minutes or until softened and starting to brown. Put onions and remaining sauce ingredients into a food processor or blender and purée.
To prepare rolls, spread 1/4 cup rice over each tortilla, leaving about a 1 1/2 inch border at the top and bottom and a 2 inch border at the sides. Divide tofu and vegetables among the 4 tortillas and top with sauce and (if desired) hot sauce.
Roll the tortillas burrito style (fold up bottom, then starting at one side, roll into a cylinder). Serve immediately.