- Preheat the oven to 375 degrees F (190 degrees C).
- Melt butter in a saucepan over medium heat. Add garlic and onion; cook for a few minutes until fragrant, but not brown. Stir in spinach, and cook for about 5 more minutes. Remove from the heat, and mix in ricotta cheese, sour cream, and 1 cup of Monterey Jack cheese.
- In a skillet over medium heat, warm tortillas one at a time until flexible, about 15 seconds. Spoon about 1/4 cup of the spinach mixture onto the center of each tortilla. Roll up, and place seam side down in a 9×13 inch baking dish. Pour enchilada sauce over the top, and sprinkle with the remaining cup of Monterey Jack.
- Bake for 15 to 20 minutes in the preheated oven, until sauce is bubbling and cheese is lightly browned at the edges.