Cattle Drive Casserole Is My New Favorite Dinner

Name: Cattle Drive Casserole Is My New Favorite Dinner
Ingredients: Cooking spray; 2 cups ( 246 g ) all-purpose baking mix (such as Bisquick); 1 1/4 cups whole milk; 2 tablespoons vegetable oil , divided; 2 pounds 85/15 ground beef; 1 small yellow onion , finely chopped (about 1/2 cup); 1 medium poblano chile or 1/2 small bell pepper, seeded and chopped (about 3/4 cup); 1 (1-ounce) envelope taco seasoning mix, or 3 tablespoons homemade; 3/4 teaspoon kosher salt; 1/2 cup mayonnaise; 1/2 cup sour cream; 2 cups ( 8 ounces ) shredded pepper jack cheese , divided; 2 cups ( 8 ounces ) shredded sharp cheddar cheese , divided; 2 (10-ounce) cans diced tomatoes and green chiles, drained (such as Rotel)