Preheat oven to 350 degrees and roast the pecans on a baking sheet for 12 to 15 minutes. While the pecans are still hot, stir in 2 tablespoons butter and salt. Reserve 1/2 cup to garnish. Process 1/2 cup pecans to a meal in the food processor with the steel knife. Add the lemon juice, Worcestershire, and butter. Process to blend well.