Cut 1 potato lengthwise into quarters; place on a 12-inch square piece of foil. Brush cut sides of potato with 1 teaspoon oil. Sprinkle with 1/4 teaspoon basil, 1/4 teaspoon salt, 1/8 teaspoon oregano, and a dash of pepper. Top each with 2 tablespoons onion and 3/4 teaspoon garlic. Reassemble potato; tightly wrap potato in foil. Repeat procedure with remaining potatoes and ingredients. Nestle potatoes in coals or on briquettes; grill for 1 hour or until tender, turning every 15 minutes.
Note: To prepare potatoes in a conventional oven, preheat oven to 475º. Place foil-wrapped potatoes on bottom rack in oven. Bake at 475º for 1 hour or until tender.