Chop the onion into small pieces and grate the garlic.
Cook in 3 tbsp oil over medium heat in a skillet until onions are translucent.
Add ground meat to skillet and continue cooking.
Season with cumin (add 2 extra tbsp for a more distinctive flavour), salt, paprika and white pepper.
Cook until no trace of pink remains in the meat.
Drain most of the fat from the pan. Leave a little for flavour and to add some liquid for the next steps.
Add tomato paste and stock, and mix well.
Let the meat simmer for at least 10 minutes to allow flavours to penetrate.
Grease your casserole dish, preferrably a 2.5- quart round dish, with 1 tbsp cooking oil.
Cut tortillas into pieces and put a layer on the bottom of the dish.
Add a layer of the meat mixture (about 1 cup).
Add a layer of shredded cheese (about 1/3 cup).
Repeat with layers of tortilla, meat, and cheese, finishing with a tortilla and a little cheese on top. Adjust layers to your preferences.
Bake covered in the oven at 350°F for 90 minutes until hot.