Start by bringing a large pot of salted water to a boil. Add the rigatoni and cook according to package instructions until al dente. Reserve about 1 cup of the pasta water, then drain the rigatoni and set it aside.
In a skillet, heat the olive oil over medium heat. Add the finely chopped garlic and sauté for about 1 minute, or until fragrant. Be careful not to let it brown too much as it can turn bitter.
Pour in the canned diced tomatoes and stir to combine with the garlic. Let the mixture simmer for about 5-7 minutes, allowing the flavors to meld together.
Slowly add the heavy cream and whole milk to the tomato mixture, stirring well. Let it simmer for another 3-4 minutes so that it thickens slightly.
Add the peeled shrimp to the skillet, stirring gently to coat them in the sauce. Cook until the shrimp turn pink and opaque, about 3-5 minutes.
Add the peas to the skillet and mix them in. Allow everything to cook together for another minute, then season with salt and pepper to taste.
Add the drained rigatoni to the skillet, tossing everything together. If the sauce appears too thick, gradually add some reserved pasta water until you reach your desired consistency.
Serve the Shrimp and Pea Rigatoni hot, garnished with fresh herbs or a sprinkle of grated cheese if desired. Enjoy the delightful explosion of flavors in every mouthful!