Heat canola oil in a medium skillet over medium heat. Add chiles and toast for 1 to 2 minutes, stirring constantly so chiles are fried well and change color.
Add onion and garlic and fry for 2 minutes, again stirring constantly.
Transfer fried ingredients to a food processor or blender and add whole tomatoes, tomato sauce, and salt. Puree until salsa is smooth with specks of chiles. Add salt to taste.
Serve at room temperature or slightly chilled.
Serve as a salsa dip or to top off your favorite tacos or tostadas.
Notes
This recipe makes 2 1/2 cups.
If it's too spicy for your liking, I recommend you add more tomato sauce.
Serve as a salsa dip or to top off your favorite tacos or tostadas.
Chile de arbol salsa can be stored in the refrigerator 3 to 5 days, or frozen for many weeks.