Combine first six ingredients. Puree in a blender. Transfer to a bowl.
In a 12 inch sauté pan, over high heat, quickly sauté shrimp with butter, garlic and tomato. Season with salt and pepper. Toss and stir constantly.
Cook tortellini in salted boiling water. Drain, and add immediately to pesto mixture.
Toss thoroughly. Spoon on plates, and top with shrimp and tomato. Serve hot.