Remove outer leaves, and cut each cabbage head into 6 wedges, leaving core portion attached to hold the wedges together. Place wedges in a large glass bowl; add 2 tablespoons water, and cover loosely with heavy-duty plastic wrap. Microwave at HIGH for 9 minutes or until tender. (For make ahead: Arrange cabbage wedges on a jelly-roll pan, and refrigerate to cool quickly and stop the cooking process. Cover and chill up to 2 days.)
Meanwhile, melt butter in a small saucepan over medium heat; add 1 teaspoon garlic, and sauté 1 minute or until garlic is golden. Add cream, and bring to a boil. Reduce heat, and simmer over medium-low heat 10 minutes or until slightly thickened. Add 1/4 teaspoon each of salt and pepper. (For make ahead: Cover garlic cream, and chill up to 2 days; reheat in microwave or saucepan.)
Combine olive oil and remaining 2 teaspoons minced garlic in a small bowl; brush oil over cabbage wedges. Sprinkle cabbage with remaining 1/2 teaspoon each of salt and pepper. Grill, covered with grill lid, over medium-high heat (350° to 400°) 12 minutes or until browned and slightly charred, turning once. Arrange cabbage on a serving platter; drizzle each wedge with about 1 tablespoon garlic cream.
Indoor Cooking Option: Broil steamed cabbage on ungreased baking sheets 5 1/2 inches from heat 24 minutes or until browned and slightly charred, turning once.