Heat charcoal or gas grill to hot (you can hold your hand 1 to 2 inches above grill only 2 to 3 seconds), or set a rack 4 inches from a broiler on high. Lightly brush both sides of bread slices with olive oil. Toast, turning as necessary, until both sides are crisp and browned, 3 to 4 minutes.
Remove bread from the grill or oven and rub each slice with the cut side of a halved garlic clove. Sprinkle with sea salt. Eat plain or add topping.
Note: Nutritional analysis is per bruschetta.