Over medium high heat, add olive oil to a dutch oven and toss with smoke sausage and onions. Saute until lightly browned. Add garlic and cook until fragrant, only about 30 seconds.
Add in broth, tomatoes, half and half, pasta, salt, and pepper. Stir to combine.
Bring to a boil, cover, and reduce heat to medium low. Simmer until pasta is tender.
Remove the pot from heat and stir in 1 cup of cheese.
Transfer to a casserole or baking dish and top with remaining cup of cheese and scallions. Broil until cheese is slightly browned and bubbly.
Serve & enjoy!