In a large pot, bring salted water to a rolling boil. Add 12 oz of pasta and cook according to package instructions until al dente, typically 8-10 minutes. Once finished, drain the pasta in a colander and set it aside.

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the diced onion and minced garlic, sautéing for about 3 minutes until the onion becomes translucent and fragrant.

Introduce 1 pound of ground beef into the skillet and sauté for 5-7 minutes until browned. Drain any excess fat.

Stir in the undrained Rotel tomatoes and the cream of mushroom soup, mixing thoroughly until well integrated and coming to a simmer over medium heat.

Pour in 1 cup of heavy cream and let it simmer for about 5 minutes, stirring occasionally until the sauce slightly thickens.

Remove the skillet from heat and stir in 2 cups of shredded cheddar cheese until melted completely into the sauce.

Adjust seasoning with salt and pepper to desired taste.

Add the drained pasta to the skillet and toss gently to coat with the creamy sauce.

Divide onto plates or into bowls and sprinkle chopped green onions on top for garnish. Serve hot.