In a small/medium bowl combine chili powder, cumin, corn starch, sea salt, onion powder, garlic powder, ground coriander, and ancho chile powder.
Add tomato paste and water to spice mixture. Stir well.
Chop up the tempeh into very small pieces.
Heat up 1 tbsp. olive oil and cook bell pepper slices for 3-4 minutes on medium heat.
Add chopped tempeh, mushrooms, and spice paste. Stir well, reduce heat to medium-low, and cook for ~7 minutes. If mixture looks too dry you can add small amounts of water.
While tempeh mixture cooks, you can heat up the tortillas, by microwaving them for 30 seconds covered with a towel.
If you are using avocado, tomato, and lime juice, you can chop them up, and mix them together.
Make your tacos with all toppings of your choice, and enjoy!