Heat your oven to 400°F so it is hot when the enchiladas are ready. Lightly spray a 9x13-inch baking pan with nonstick spray. Set the pan close to your workspace so assembly is quick.
Warm the olive oil in a skillet over medium heat. Add the diced onion and green pepper, and cook until they turn tender. I usually stir them every minute or so to prevent browning.
Stir in the minced garlic and cook for just one more minute. You will smell it right away, and that is your cue to move on. Do not let it burn, because burnt garlic tastes bitter.
Add the shredded turkey to the skillet and toss everything together. Season with salt and pepper, then taste a small bite. If the turkey was already seasoned, go easy on the salt.
Spread about ½ cup of enchilada sauce across the bottom of your baking pan. This thin layer keeps the tortillas from sticking. It also adds moisture from below while the pan bakes.
Spread roughly 1 tablespoon of enchilada sauce over each tortilla. If you use corn tortillas, warm them first so they bend without cracking. I hold mine over a gas flame for a few seconds, but a skillet works too.
Spoon about ¼ cup of the turkey mixture onto each tortilla. Add roughly 2 tablespoons of shredded cheese on top. Roll it up snugly and place it seam side down in the pan.
Pour the rest of the enchilada sauce evenly over the rolled tortillas. Sprinkle the remaining cheese across the top, covering every edge. This is the layer that turns golden and bubbly.
Cover the pan with foil and bake for 15 minutes. Remove the foil and bake for 5 to 10 more minutes, until the cheese is browned and bubbly. Do not overbake, or the tortillas can turn soggy.
Let the pan sit for about 5 minutes after it leaves the oven. This helps the sauce settle so each enchilada holds together. Scoop them out with a wide spatula and add your favorite toppings.