Cook pasta according to package instructions and set aside

In a nonstick skillet on medium heat, heat butter and oil

Saute shallots and garlic until fragrant, about a minute

Add marinara sauce to the mixture and bring to a simmer

Once simmering add heavy cream and mix well to combine until a pink colored is achieved with the sauce

Once combined, add a 1 /4 cup of shredded cheese and stir until melted

Combine cooked pasta shells with sauce, stirring well to combine, add pasta water as needed to get the desired consistency

Top the pasta with the remaining cheese and melt in the oven on broil for 1 minute

Serve warm while cheese is nice and melty and enjoy