In a large pot of boiling salted water, cook the capellini until just barely tender; drain, rinse, and place in a large bowl. Toss the capellini with a little olive oil to keep it from sticking together.
Meanwhile, in a large skillet, heat 3 tablespoons of olive oil and melt the butter over medium heat; add the shrimp-and garlic and sauté until the shrimp just turns pink. Stir in the lemon juice, basil, parsley, oregano, dillweed, and chicken stock; reduce the heat and simmer until heated through.
Pour the shrimp mixture over the capellini and toss gently until the capellini is lightly coated. Season with pepper and serve.