Absolutely not! They hold up extremely well overnight to give you a head-start the next day, but you can pop them into the oven the minute you’ve finished assembling them.
Brown the bacon
Toss the bacon into a skillet and cook until golden brown. Transfer it to a plate lined with paper towels to cool, and discard the excess bacon fat.
Cook the ham
Add the ham to the skillet. Cook it until lightly browned. Remove the ham from the skillet and set it aside.
Sauté and combine
Add the onion and red pepper to the skillet. Sauté the veggies until softened. Then add garlic. Transfer the veggie mixture to the bowl with ham. Stir in the bacon.
Take a tortilla and add the bacon-veggie mixture. Roll it up and place it seam-side down in the prepared baking dish. Repeat and set aside.
Whisk the eggs
In a small bowl, whisk the eggs and milk until thoroughly scrambled. Pour this egg mixture over the unbaked enchiladas. Cover and refrigerate overnight.
Prep the oven and add sauce
The following day, preheat the oven. Pour enchilada sauce over the tortillas and generously top them with cheese.
Pop them in the oven for until the eggs have fully set. Remove them from the oven, garnish with your favorite toppings, and enjoy!