First, make the sauce. Place tomato paste and broth in a medium saucepan over medium heat.
In a small bowl, mix together the oil and flour with a fork, then add it to the saucepan with the tomato paste and broth. This will help thicken it.
Add the remaining ingredients to the saucepan mixture and stir to combine. Bring to a gentle simmer, cooking until sauce thickens slightly, then turn down the heat to low to keep warm while you make the rest of the enchilada components.
Spray a 9-by-13-inch baking dish with cooking spray and set aside.
If you are planning on serving the enchiladas right away, preheat the oven to 350 degrees Fahrenheit.
Place a medium saute pan over medium heat on the stove and add 1 tablespoon oil. Once oil is warm, add bell peppers and onions. Saute until onions are translucent and fragrant, then move the mixture to a separate mixing bowl.
Using the same saute pan, scramble the eggs using the leftover oils and juices from the vegetables. Once eggs are cooked, remove to your other mixing bowl.
Lay tortillas out onto a large prep space so you can assemble them all at once. Divide the vegetables, shredded meat and eggs evenly among the 8 tortillas.
Roll each one up and tuck it into the prepared baking dish. It’s okay if they’re a bit snug.
Once all of the tortillas are tucked into the baking dish, top them with the enchilada sauce, then with the shredded cheese.
At this point, you can cover and freeze or refrigerate the enchiladas until you are ready to serve them OR you can bake them right away.
When you’re ready to bake, place the enchiladas on a rimmed baking sheet (to catch any drips) and pop them into a 350-degree oven for 15-20 minutes. If your enchiladas are frozen, you may need closer to 30-35 minutes. To make the cheese on top extra-bubbly and brown, turn the broiler on for the last 5 minutes or so of baking.
Once enchiladas are warmed through, remove from the oven and top with fresh cilantro and sliced avocado before serving.