Heat a 12-inch nonstick ovensafe skillet over medium high heat. Add oil, pancetta, and garlic to the pan. When pancetta browns at edges and begins to crisp, add arugula. Wilt arugula, stir in tomatoes. Beat eggs together with half-and-half. Whisk in salt and pepper. Pour eggs over fillings and let eggs set. Using a spatula, raise eggs off the bottom of the skillet, allow more of the liquid egg to settle. When the frittata has set, transfer to oven and cook 10 to 12 minutes until top is deep golden brown. Remove the frittata and let it stand 5 minutes. Cut into wedges and serve.