Combine quinoa, vegetable broth, and salt in a small saucepan. Bring to a boil, reduce to a simmer, cover, and cook for 12 to 13 minutes. After that time, remove the pan from the heat and let steam until ready to use. Alternatively, use about 1 cup leftover quinoa if you have that available.  

To make onions, cut into ⅛” thick half circles. Heat over low the olive oil in a skillet. Place sliced onions in skillet and cook until they begin to brown, 10-15 minutes. Once onions are cooked, stir in balsamic vinegar and continue to cook until vinegar reduces down, about 5 minutes. Stir in the chard and continue to cook until wilted, another 5 minutes or so.

Preheat oven to 400˚F. While the onions are cooking, combine the eggs, cream, salt, and pepper in a bowl. Whisk well to combine.

When the chard is cooked down, add in the quinoa and pour the eggs over the mixture and stir. Let cook for a couple minutes, just to let the bottom set. Sprinkle with the feta

Transfer the frittata to the oven and bake for 12 to 15 minutes. The frittata should be puffed and browning.