Heat the oil over medium high heat in a large skillet. When hot, add the onions with a pinch of salt. Cook, stirring occasionally, for 10 minutes.

Add the garlic and cook another 2 minutes.

Add the mushrooms in batches so that they brown instead of steam. Add a pinch of salt with each batch. If at any point the mushrooms or onions start to stick or scorch, splash some beer (a tablespoon or two) into the pan.

Let the mushrooms cook about 3-5 minutes per batch, scooting each batch out of the way when you add the next batch (leave it all in the pan).

Preheat the oven to 350 F.

Add the chopped bell peppers and the oregano, cumin and ancho chile powder. Stir and let cook for 1 minute.

Add the rest of the bottle of beer, along with all of the beans. Stir it all together and bring to a boil. Add a pinch or two more of salt.

Reduce the heat to simmer briskly for 7 minutes.

Lightly grease a 9X13 casserole dish.

Scrape the onion-bean-mushroom mixture into the casserole pan.

Sprinkle with all of the Monterey Jack cheese and about half of the cheddar cheese. Spread crumbled tortilla chips over the casserole. Sprinkle the remaining cheddar cheese evenly over the tortilla chips.

Bake at 350 F until the cheese is melted and the casserole is bubbling under the tortilla chips. I baked after placing the casserole in the refrigerator overnight, so mine took closer to an hour, but if you start with hot ingredients, it will take about 20-30 minutes.

Let the casserole rest for 5-10 minutes before serving with sour cream and salsa.