Bring a large pot of salted water to a boil. Add your pasta of choice and cook according to package instructions until al dente. Drain and set aside, keeping it warm.
In a large skillet over medium heat, add olive oil, diced onion, and minced garlic. Sauté for about 3 minutes, or until the onion becomes translucent and fragrant.
Add the ground beef to the skillet. Cook until browned and fully cooked through, breaking it into crumbles with a spatula. Drain any excess fat for a lighter sauce.
Stir in the undrained Rotel tomatoes along with the cream of mushroom soup. Mix everything until thoroughly combined, allowing the skillet to simmer for a minute.
Pour in the heavy cream, stirring well. Let the mixture simmer for about 5 minutes, or until it thickens slightly. Stir occasionally to prevent sticking.
Add shredded cheddar cheese to the skillet, stirring constantly until melted and the sauce becomes creamy and smooth.
Season the sauce with salt and pepper, adjusting to your liking. Give it a taste test to ensure the flavors are just right.
Add the warm pasta to the sauce in the skillet, tossing until every piece is evenly coated in the creamy mixture.
Plate your delicious pasta and garnish with chopped green onions if desired for a pop of color and flavor.