Heat olive oil in a medium saucepan over medium heat. Add garlic and cook, stirring, for 30 seconds.

Add all remaining ingredients: tomato sauce, broth, and spices and stir.

Bring to a simmer, reduce heat to low, and cook at a low simmer for 10 minutes, stirring occasionally.

Strain the sauce through a fine sieve to take out garlic and onion (or optional to puree the sauce, it will just be a bit thicker. 

Enchilada sauce can be used immediately or stored for future use. To store, let it cool and then refrigerate in an airtight container for up to 4 days or freeze for up to 3 months.