Swiss Chard Frittata recipes

Name: Swiss Chard Frittata recipes
Ingredients: 24 cherry tomatoes; 2 cloves garlic, smashed; 2 tablespoons extra-virgin olive oil; 1 tablespoon balsamic vinegar; 1 teaspoon fresh thyme leaves; 1/2 teaspoon light-brown sugar; 1/4 teaspoon coarse salt; 18 large eggs; ground black pepper; coarse salt; 2 to 3 tablespoons extra-virgin olive oil; 2 large white onions, halved and sliced crosswise into 1/4-inch-thick slices; 6 to 8 ounces Swiss chard, stems sliced thin, leaves sliced into ribbons; 3/4 cup cow's milk feta, crumbled