Place tofu onto a plate and cover with another plate. Set a 3- to 5-pound weight on top. Press tofu for 20 to 30 minutes; drain and discard the liquid.
STEP 3
In a bowl, mix sherry vinegar, soy sauce, olive oil, garlic powder, salt, cayenne, marjoram, and black pepper.
STEP 4
Cut tofu into 6 thick slices and place in a baking dish. Pour marinade over tofu, turning to coat, and chill for at least 30 minutes, up to 48 hours.
STEP 5
Preheat the grill to high heat. Reduce heat to medium and lightly oil the grate.
STEP 6
Remove tofu from marinade and shake off excess; reserve remaining marinade for sauce.
STEP 7
Cook tofu on the grill for 10 to 15 minutes, turning once until well browned.
STEP 8
Boil reserved marinade in a saucepan; simmer until it reduces to about 1 cup. Pour over tofu and serve hot or warm.