This is a garlic-lover's delight!

3 pounds medium uncooked shrimp, peeled and
    de-veined, leaving tails
2/3 cup unsalted butter or margarine
2/3 cup extra-virgin olive oil
4 scallions, chopped, including tops
6 large garlic cloves, minced
1 1/2 tablespoons fresh lemon juice
1 tablespoon white wine Worcestershire sauce
1/2 teaspoon Tabasco