4tablespoons (1/2 stick)unsalted butter, plus more for the baking dish
2medium white onions, chopped (2 cups)
2clovesgarlic, minced or put through a garlic press
1jalapeño or serrano pepper, finely chopped (seeding optional if you want less heat; may add more to taste)
2poundsmixed mushrooms, (such as white button, baby bella, portobello and shitake), cleaned, dry part of stem removed, sliced
1teaspoonkosher or coarse sea salt, or more to taste
1/4teaspoonfreshly ground black pepper
2tablespoonschopped cilantro, leaves and thin part of stems
2tablespoonschopped parsley, leaves and thin part of stems
1cupMexican cream, or Latin-style cream, or heavy cream
8ounces (about 2 cups)farmers cheese or queso fresco, crumbled
6cupscooked white or brown rice
1cupfreshly grated queso anejo, Parmigiano-Reggiano, or Romano
Heat the butter and oil in a large, deep 12-inch skillet over medium heat. Add the onions and stir to coat; cook for about 12 minutes, stirring occasionally, until they are translucent and the edges begin to brown. Add the garlic and jalapeño or serrano pepper; cook for 2-3 minutes, until softened. Add all of the sliced mushrooms; sprinkle with salt and pepper, and gently combine with the onions. Cover and cook for 5 to 6 minutes, until the mushrooms have exuded their juices and the flavors have melded. Uncover and cook for 7 to 8 minutes or until the juices have evaporated.
Add the cilantro and parsley, stirring to combine. Add the cream and the crumbled queso fresco or farmer cheese; stir until the mixture is thoroughly combined and the cheese has melted. Continue cooking for 3 to 4 minutes, adjusting the heat to keep the mixture barely bubbling at the edges. It should still be very saucy. Turn off the heat.
Preheat the oven to 375°F. Use a little butter to grease a 9-by-13-inch baking dish or the equivalent.
Spoon the cooked rice into the baking dish and level it out without pressing down hard. Pour the mushroom-cilantro mixture on top and gently spread to level it. Sprinkle with the grated cheese. Bake for 15 to 20 minutes or until the cheese has melted and gently browned.