Prepare the Mushrooms: Preheat your oven to 350°F and set out a 9×13-inch baking dish. Gently pop off the stems of the mushrooms and discard or save them for later use. Use a damp paper towel to wipe off any dirt from the mushroom tops—do not rinse them in water.

Prepare the Cheese Filling: In a medium bowl, mix together the cream cheese, smoked cheddar cheese, diced green chile, onion, garlic, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Stir well until fully combined.

Stuff the Mushrooms: Use a spoon to fill each mushroom cap with the cheese mixture, packing it in tightly. Don’t worry if some filling overflows—just be mindful not to overstuff them.

Coat with Parmesan: Press the top of each cheese-stuffed mushroom into grated Parmesan cheese to form a crust, then place the mushrooms in the prepared baking dish, cheese-side-up. They can be snug in the dish, as they will shrink while baking.