3 bolillo-style rolls or 1 long baguette
2 tablespoons olive oil
1 yellow or white onion, chopped 2 to 3 carrots, chopped
1⁄2 teaspoon salt
6 cloves garlic
8 ounces white or baby bella mushrooms, chopped
2 tablespoons tomato paste
1 tablespoon dried oregano
1 teaspoon ground cumin
1 1⁄4 pounds ground beef
1 (10-ounce) package pork chorizo
1 (28-ounce) can crushed or pureed tomatoes
6 tablespoons unsalted butter, softened
9 tablespoons crema, plus more for serving
1 1⁄2 cups crumbled queso fresco