Heat oven to 350 f. Combine tuna, mayonnaise, celery, green pepper, olives, and thyme; mix lightly. For each sandwich, top bread slice wtih 1/4 c. tuna mixture; cover with slice of cheese. Bake at 350 F. for 10 minutes or broil until cheese melts. 6 sandwiches, each 139 calories, 13 g protein, 18 g carbo., 2 g fat, 17 mg cholesterol, 637 mg sodium