Heat the oven to 400 °F and grease an 11 x 13 casserole dish well. The dish should be fully coated so the meat and cheese layers release easily after baking.

Put the ground turkey or beef in the dish, add the taco seasoning, and mix it together directly in the pan before spreading it out evenly. Bake for 20 minutes, until the meat starts to cook through and releases liquid into the dish.

While the meat bakes, stir together the cottage cheese, salsa, and 1 cup of the shredded cheddar cheese in a mixing bowl. The mixture should look creamy and spoonable, not stiff or dry.

Take the dish from the oven, carefully drain off the cooking liquid, and use a potato masher to break the meat into small crumbles right in the pan. The meat should look evenly seasoned and no longer sit in visible pools of grease or liquid.

Spread the cottage cheese mixture over the meat, then scatter the remaining cheese across the top. Cover the surface from edge to edge so the casserole bakes into distinct, creamy layers.

Return the dish to the oven and bake for 15 to 20 minutes more. Pull it when the meat is cooked through and the cheese is hot and bubbling vigorously around the edges.