Meanwhile, in 12-inch skillet, cook bacon over medium-high heat 8 to 11 minutes or until crisp; drain on paper towels. Crumble bacon; set aside. Reserve 1 tablespoon bacon drippings in skillet. Add leeks to drippings; cook over medium heat 5 to 7 minutes, stirring occasionally, until tender. Remove from heat. Stir in 1/2 cup of the cheese, the chopped thyme, salt and pepper.