Anytime Frittata with Swiss Chard and Tomatoes

1. Prepare Swiss chard: Clean and check leaves thoroughly. Cut off long stems from Swiss chard leaves.  Chop stems and set aside.  Chop leaves into 1-2 inch strips and set aside.
2. Beat eggs in a large bowl until well blended.  Season to taste with salt and pepper; set aside.
3. Preheat broiler.
4. Heat oil in a large frying pan (oven-safe) over medium high heat until oil is hot.  Add reserved stems, onion, and garlic.  Season with salt and freshly ground black pepper to taste.  Sauté for about 5-7 minutes until onions are translucent and soft.
5. Add beaten eggs. Use spatula to stir and gently form large curds. Allow eggs to set for about 2 minutes.  Add reserved chard leaves and chopped tomato; distribute evenly amongst eggs.  Sprinkle evenly with parmesan cheese.
6. Transfer pan to broiler.  Finish cooking under broiler for another 3-5 minutes, or until eggs are cooked and cheese is nicely browned.
7. Remove from broiler. Cut into wedges and serve warm.