Have your pasta cooked and keep warm.
Heat butter and olive oil over medium- high heat in a medium skillet.
Season the shrimp with Old Bay Seasoning and place in skillet.
Add the garlic and cook the shrimp on both sides until pink.
Take care not to let the garlic burn. Remove shrimp and garlic to a small bowl or plate.
Add sliced peppers and onions seasoning with a bit of Old Bay Seasoning.
Saute the vegetables over medium-high heat for about 5 minutes. You want the peppers to be tender-crisp, not mushy.
Next add the half-and-half and Parmesan cheese. Turn down heat to medium and simmer for about 5 minutes. The sauce will thicken some as it cooks.
Add shrimp and garlic back to the skillet and continue to simmer for about 4-5 more minutes.
Taste sauce to see if you need to add more seasoning or salt and pepper to your tastes.
I just use the Old Bay seasoning and sometimes I will add more if needed.
At this point, add cooked pasta, stirring to coat pasta with sauce. The sauce just coats the mixture, it will not be "puddling" like a normal Alfredo or marinara sauce would be
Add a sprinkling of shredded Parm and serve.