Swiss Chard and Onion Frittata

Use the tender chard stalks; just cut them into cubes and cook with the leaves. Serve with a simple side dish for a great low-calorie dinner.
Preheat a 10-inch nonstick skillet over medium-low heat. Add 2 teaspoons of olive oil to the skillet; stir to coat. Add the thinly sliced onion; cook for 12 minutes or until the onion is tender, stirring occasionally. Add the chard; cook for 10 minutes or until the chard is tender, stirring occasionally. Sprinkle with 1/4 teaspoon salt and black pepper.Combine the parsley, 2 tablespoons basil, garlic, eggs, and remaining 1/4 teaspoon salt, stirring with a whisk. Add the chard mixture to the egg mixture. Add 1 ounce of Gruyere cheese.Preheat the grill to high heat.Wipe the pan clean with a paper towel. Return the skillet to medium-high heat. Add the remaining 2 teaspoons of oil to the pan; stir to coat. Add the egg mixture to the pan; cook for 30 seconds. Reduce heat to low; cook, without stirring, for 4 minutes or until the eggs are half cooked. Sprinkle the egg mixture with the parmesan cheese and the remaining 5 ounces of Gruyere cheese.Place the baking sheet under the grill. Bake for 1 minute or until the eggs are fully cooked and the cheese is lightly browned. Remove the mold from the oven. Run a silicone spatula around the edge and under the frittata to remove from the pan; place the frittata on a plate or cutting board. Sprinkle with the remaining 2 tablespoons of basil. Cut the frittata into 4 slices.