Combine all sauce ingredients in a blender and puree until smooth.
Heat a large skillet to medium-high heat. Add 1 tablespoon oil of choice. When oil is shimmering, add tempeh. Saute for 1 minute without stirring, allowing it to brown.
Add 1/2 of your sauce and stir to incorporate and cooked grain of choice. Sauté another 8-10 minutes, stirring. Until tempeh has soaked up sauce. Remove from heat.
Assemble burritos (you can heat these in the oven slightly beforehand). Place 1/3 cup tempeh/grain mixture on the left hand side of a tortilla, leaving a 1 inch margin around the edges. Add remaining toppings of choice and an extra drizzle of sauce, being sure to keep at least 1/2 of the tortilla empty.
To roll, tuck in the bottom and top 1 inch of the tortilla. While tucking, roll tortilla closed starting from the food-filled side moving towards the empty side. Hold firmly for a few seconds to stick. Serve immediately.