Marinade: 1/4 cup soy sauce 1 or 2 cloves garlic, minced 2 tsp sugar 1/2 tsp dry mustard (or 1 tsp Dijon or prepared mustard) Barbecue sauce (anchovy-free for vegetarians)
Slice tofu 1/4- to 1/2-inches thick and place in shallow dish.
In small bowl, combine soy sauce, garlic, sugar and mustard; drizzle over tofu. Let marinate in refrigerator for at least 2 hours or overnight.
Drain tofu; grill on lightly greased barbecue rack over low heat for 2 minutes. Carefully turn over using a wide spatula; grill 2 minutes. Brush with barbecue sauce; continue grilling, 2 minutes a side.