Cover roast with the seasoning (cumin, salt, pepper, garlic powder, paprika, ground ginger, and cayenne) diced tomatoes, tomato sauce, chillies, onion, and garlic.
Heat a flat skillet or griddle over medium high heat. Add a cassava flour tortilla to the pan and let the tortilla heat until it develops little bubbles. Remove from the heat (without burning your fingers!). Place desired amount of shredded tri-tip onto tortilla, followed by desired toppings (listed above in ingredients list).