Heat the olive oil in a medium saucepan over medium heat. Add in the onions and season with salt. Sauté until translucent, about 5 minutes.
1 tablespoon olive oil, 1 small yellow onion, 1/2 teaspoon kosher salt
Wisk in the cumin and chili powder and toast for 30 seconds.
1 1/2 teaspoons cumin, 2 teaspoons chili powder
Whisk in the all purpose flour.
1 tablespoon all purpose flour
Slowly whisk in the chicken stock, adding just a little at a time. Stir in the tomato sauce. Stir in the minced garlic.
1 cup chicken broth, 15 ounces tomato sauce, 2 cloves garlic
Bring to a simmer and cook for 5 minutes. (I like to use a screen while it simmers.) Either leave it as is or transfer to a blender to puree. Use immediately, store in an airtight container in the refrigerator for up to 1 week, or freeze in an airtight container for up to 3 months.