Creamy Shells with Peas and Prosciutto

I love tomato-based pasta sauces, but Seth likes cream sauces, so sporadically I try out a recipe for him. Tonight I made the America's Test Kitchen's Creamy Shells with Peas and Prosciutto. It was a winner and will be making future appearances at dinner.

The recipe says it serves four, but I think that's a bit off. It calls for a pound of small pasta shells, and between the butter and whole-milk ricotta, it's a filling dinner plus lots of leftovers. I also cut down on the amount of salt because prosciutto itself is so salty.

Creamy Shells with Peas and Prosciutto
from the America's Test Kitchen

Ingredients
1 cup whole milk ricotta
1/2 cup Parmesan cheese, grated
2 T unsalted butter, cut into 8 pieces
Salt
Pepper
4 ounces thinly sliced prosciutto, cut into 1/4-inch strips
1 T extra-virgin olive oil
1 onion, minced
2 garlic cloves, minced
1 pound small pasta shells
2 cups frozen peas
1 T fresh lemon juice

Directions

• Bring 4 quarts water to a boil.
  
• Combine the ricotta, Parmesan, butter, 1/4 teaspoon salt, 1/2 teaspoon pepper in a bowl that's big enough for the pasta.
  
• Cook the prosciutto and olive oil in a nonstick skillet over medium-high heat, about five minutes; or until prosciutto is well-browned and crisp. Place prosciutto on paper-towel-lined plate. Leave the oil in the skillet.
  
• Add the onion to the skillet and cook in oil over medium heat until soft, about five minutes. Add the garlic and cook until fragrant. Stir the onion/garlic mixture to the ricotta mixture.
  
• When the water is boiling, add 1 tablespoon salt and pasta. Cook al dente. Add the peas during final 30 seconds.
  
• Reserve 3/4 cup pasta cooking water. Drain shells and peas. Whisk lemon juice and 1/2 cup of the pasta water into the ricotta mixture until smooth. Add the pasta/peas and toss to coat. Salt and pepper to taste.
  
• Add the remaining pasta water as needed to loosen the sauce. Sprinkle the prosciutto over the pasta and serve.