This sauce can be made in advance; it will keep for up to 2 days in a covered container in the refrigerator. Heat gently before tossing with hot, freshly cooked pasta.
8 ounces vermicelli
½ cup ricotta cheese
½ cup plain yogurt
½ cup coarsely chopped walnuts, preferably toasted
¼ cup freshly grated Parmesan cheese
1 tablespoon butter, softened
2 cloves garlic, minced
½ cup minced fresh flat-leaf parsley
1 tablespoon minced fresh basil or
1 teaspoon dried basil
½ teaspoon freshly ground pepper, or to taste
Freshly ground pepper, freshly grated Parmesan cheese, cherry tomatoes, and steamed broccoli florets for garnish
Bring a large pot of water to a boil over high heat; add the vermicelli. When the water returns to a boil, stir occasionally to separate the pasta. Reduce the heat to medium-high and cook until al dente, about 9 to 11 minutes, or according to package instructions.
White the pasta is cooking, process the ricotta cheese, yogurt, walnuts, Parmesan, butter, and garlic in a food processor until smooth. Stir in the remaining ingredients. Transfer to a small nonstick saucepan; heat, stirring occasionally, just until warm.
When the pasta is done, drain well. Return to the pot; add the sauce and toss. Taste and adjust the seasoning.