Combine first 6 ingredients; stir in 1 tablespoon parsley.
Place bread slices on grill rack; grill 1 minute on each side or until lightly browned. Rub one side of each bread slice with cut sides of garlic. Discard garlic. Brush oil evenly over garlic-rubbed sides of bread slices. Spread 1 1/2 teaspoons ricotta mixture over each bread slice; top each serving with 1 tomato slice. Sprinkle salt and remaining 1 teaspoon parsley evenly over the tomatoes. Serve immediately.