Add oil to an oven safe skillet. Saute sausage and onions until the onions are soft about 5 minutes.
Add garlic for about 30 seconds while stirring until fragrant.
Add to the skillet broth, tomatoes, cream, pasta, salt and pepper. Stir to combine. Put lid on the skillet, bring to a boil and simmer until pasta is cooked, about 15 minutes.
When pasta is cooked, remove from heat.
Add 1//2 cup cheese to the pasta and stir until it is melted and incorporated. Add remaining cheese to the top and place skillet under broiler until cheese is bubbly and brown.
Top with scallions and serve.
Notes
If you would like a less spicy version, you may used petite diced tomatoes instead of the Mild Ro-Tel Tomatoes.