Add ground beef to a cast iron skillet and bring to medium-high heat. Move around pan until ground beef is cooked through. Drain excess grease.
Add tomato paste, chili powder, cumin, onion powder, garlic powder, kosher salt, ground black pepper and oregano. Stir to combine. Add water, 1 tablespoon at a time, as needed to thin the mixture out.
Take a shell of your choice and add the ground beef mixture as well as any toppings of your choice (listed in the Ingredient section above).
Notes
Dairy-Free: to make these dairy-free choose a dairy-free cheese and a dairy-free sour cream.
Gluten-Free: to make these gluten-free choose a gluten-free shell like corn tortillas or Siete brand tortillas.
Grain Free Shells: I love the Siete brand hand shells!
Storage: store leftover ground beef mixture in an airtight container in the refrigerator for up to 3 days.