Coat a 9 by 13-inch baking dish with softened butter.
In a large, deep skillet, heat the olive oil over medium heat and saute the onions and garlic for 5 minutes. Stir in the cream and cook for 1 minute.
Pour a small amount of the onion-cream mixture on the bottom of the buttered baking dish. Crumble 6-ounces of cheese over the bottom. Layer the potatoes, overlapping them a bit, on top of the cream and cheese. Season with salt, and pepper, to taste.
Pour more onion-cream mixture on top of potatoes and sprinkle with a handful of grated Parmesan. Top with 6-ounces more of Red Hawk cheese. Repeat this step until all the potatoes and onion-cream has been used up.
Sprinkle the top of the gratin with the reserved Parmesan cheese. Cover the gratin with aluminum foil and bake for 1 hour. Remove the foil then bake for 30 to 45 minutes more, or until the cheese on top is golden brown and the gratin in bubbling.