Step 1

Preheat oven to 375ºF. Heat olive oil in a large skillet over medium heat. Add onion and garlic. Season with salt and pepper. Cook, stirring occasionally, until onion is soft, 6 to 8 minutes. Add chiles and cook, stirring occasionally, until liquid has cooked off, 3 to 4 minutes. Add taco seasoning and cook, stirring, until fragrant, about 1 minute. Add beef and cook, breaking it up with a wooden spoon, until no longer pink, 4 to 6 minutes; transfer to a bowl.

Step 2

Wipe the skillet clean. Heat canola oil in skillet over medium-high heat. Fry tortillas, one at a time, turning once, until golden brown, about 1 minute.

Step 3

Place 1 cup enchilada sauce in the bottom of an 8- by 8-inch broiler-proof baking dish. Combine Monterey Jack and Cheddar in a bowl. Working one at a time, dip fried tortillas in sauce, then fill with 1/3 cup meat mixture and a sprinkle of cheese. Roll up and place, seam sidea down, in prepared pan. Top with remaining sauce and cheese.