Preheat oven to 400 degrees, cut the tops off the heads of garlic to expose the cloves and drizzle with olive oil and sprinkle with salt and pepper. Wrap in tin foil and toss into the oven for 40-50 mins.
Once roasted, squeeze the garlic into a bowl and mash it, lower oven temp to 375
Then mix in the rest of the ingredients, reserving ½ cup of the cheese, and stir to combine everything really well.
Pour into a cast iron skillet and top with the remaining cheese and bake for 20 - 25 minutes until it is brown and bubbly on top.*