Coming from the Catalonia region of Spain, Romesco is a versatile sauce made from nuts and red peppers. It works great on roast chicken, grilled vegetables, or this Spanish-inspired pasta adorned with shaved Manchego cheese and slivered almonds.
Place tomato, bell peppers, hazelnuts, parsley, vinegar, salt, paprika, cayenne, black pepper, garlic, and 1/2 cup of the almonds in a blender; pulse until finely chopped, 6 to 8 times. With processor running, slowly pour oil through opening in lid. Process until smooth, and set aside.
Cook pasta according to package directions; drain. Combine pasta with tomato mixture in a large skillet; cook over medium-high, stirring often, until heated through, about 3 minutes. Cover; remove from heat.
Melt butter in a separate large skillet over medium-high. Add shallot; cook, stirring often, until translucent, 1 to 2 minutes. Add scallops; cook, stirring occasionally, until slightly firm, about 2 minutes. Remove from heat.
Divide pasta mixture among 4 bowls. Arrange scallops over pasta; top with cheese, chives, and remaining 1/4 cup almonds. Serve immediately.