1. Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
2. Deseed the squash and set aside.
3. Mix salt, chili powder, red pepper flakes, and cumin. Remove one teaspoon of this mixture and mix with one tablespoon oil (you can double this mixture and use as an
option at the end). Rub the oil-spice mixture over the squash. Place cut side down on the baking sheet and bake for 20–30 minutes, until almost soft. (The exact amount of time will depend on how thick-skinned your squash is.)
4. Meanwhile, mix remaining spice mixture with chopped meat and spinach.
5. Heat two tablespoons of oil in a frying pan and add the meat mixture. Add the tomato paste and sauce. Sauté until the meat is browned but not fully cooked, about 10–15 minutes.
6. Remove squash from oven and stuff the meat mixture into the hollow cavities. Return the stuffed squash to the pan, face up. Cover and bake covered for 20 more minutes.