Set your oven to 400°F (204°C).

Bring a large pot of salted water to a rolling boil. Add the dry elbow macaroni and cook uncovered, stirring occasionally, for 9 to 11 minutes until mostly cooked but still slightly firm. Drain pasta and set aside.

While the pasta cooks, heat a large skillet over medium heat and add ground beef. Season the beef with oregano, sea salt, black pepper, chili powder, and ground cumin. Cook until browned and no longer pink, about 5 minutes.

Add butter, chopped onions, minced garlic, and tomato puree to the cooked beef. Stir until all ingredients are fully combined and fragrant.

Add the drained pasta to the skillet with the beef mixture. Stir in the heavy cream, chicken stock, dried parsley, dried basil, 1 1/2 cups Monterey Jack cheese, and 1 cup cheddar cheese. Mix thoroughly to coat the pasta and beef.

Pour the combined mixture into a 9x13-inch casserole dish. Evenly sprinkle the remaining 1/2 cup Monterey Jack and 1 cup cheddar cheese on top.

Place the casserole in the preheated oven and bake for 15 to 20 minutes, or until the top cheese layer is melted, golden brown, and bubbly.

For a more saucy casserole, serve immediately. For a casserole that holds its shape better, let it rest for 10 minutes before cutting and serving.