First, make a batch of my taco meat recipe. It is the perfect amount for this dish. You can make it the day before to save time and then this casserole comes together super fast. If using my homemade enchilada sauce, have that ready as well.
Preheat the oven to 350°F (°177C) and spray a 9x13 dish with nonstick spray.
Add the broth to a medium pot and bring to a boil. Once boiling, whisk in the salt and polenta slowly and remove from the heat. Whisk for a couple of minutes and it should start to thicken rather quickly.
Stir in the enchilada sauce immediately into the polenta until smooth. Taste and add any more salt if needed.
Pour the creamy polenta into the dish and spread out evenly.
Top the polenta with the taco meat and spread it out evenly as best you can.
Drizzle the liquid mozzarella cheese all over the top.
Bake for 25 minutes until bubbly and the cheese is firm.
Let the casserole sit for about 10 minutes, as it will be extremely hot to eat right away. This will also allow the polenta to firm up a bit. The polenta portion is meant to be creamy, as I don't like it super firm. But it will get more firm over the next hour and of course with any leftovers stored in the fridge.
Top with green onions and enjoy!
Notes
Enchilada sauce:
Use my homemade recipe or store-bought. If using store-bought, I would suggest a "mild" variety, as the mild is still fairly spicy and my taco meat is spicy, so you don't want the overall dish to be TOO spicy. Most commercial enchilada sauces are vegan, so just double check the label.