Preheat your oven's broiler to high.In a well seasoned cast iron skillet, heat the olive oil over medium heat. Add 1½ cups of the grilled vegetables and the minced garlic; cook until heated through, about 2-3 minutes.While the vegetables are cooking, beat together the eggs, heavy cream, salt and pepper to taste. Pour the egg mixture into the skillet and cook over medium-low heat using a heatproof spatula to stir and push the egg from the edges of the pan towards the center in deliberate strokes to form large curds. Continue until the eggs are almost cooked, wet on top but otherwise set, about 2-3 minutes.Pile the remaining ½ cup of grilled vegetables on top in the center of the frittata then sprinkle with the cheese.Place the skillet under the broiler and cook until the eggs are set and the top has puffed slightly like a souffle, about 2-3 minutes. Watch closely so that your frittata doesn't burn!To serve, top the frittata with the cilantro and peppers and a few grinds of fresh cracked pepper.