Preheat the oven to 425°F. Whisk the eggs and half-and-half together in a mixing bowl until light and frothy. Set aside.

Cook the bacon in a medium (10-inch), oven-proof, nonstick skillet until crisp. Transfer to a paper towel-lined plate and drain all but 1 tablespoon of the fat from the pan.

Set the pan back on the stove over medium heat and add the olive oil. Add the onion and sauté until soft and translucent, 3 to 4 minutes.

Add the garlic and continue cooking until softened, 1 to 2 minutes longer. Add the tomatoes and 1 tablespoon of the parsley.

Add the salt and a few grinds of black pepper, combine well and continue cooking for 1 minute longer.

Stir in the eggs and using a rubber spatula, stir and scrape the bottom of the pan until the eggs form large, wet curds, about 2 minutes.

Scatter the bacon over the eggs, then smooth the mixture so it's evenly distributed in the pan. Stop stirring and wait about 30 seconds to allow the bottom to set.

Remove from the heat and sprinkle the cheese over the top of the frittata.

Bake until the frittata is slightly puffed and the cheese has melted, 5 to 7 minutes.

Remove from the oven, sprinkle with the remaining parsley and let stand for about 5 minutes.

Use a spatula to loosen the frittata around the edges and gently slide it onto a serving platter. Cut into wedges and serve immediately.