Adapted from https://thefeedfeed.com/famtotable/rainbow-chard-frittata
Preheat the oven to 400 ̊F. In a mixing bowl, beat the eggs and add a pinch of salt.
In a large non-stick skillet gently sauté the onions in the oil until translucent, or about 10 minutes. Add the chopped rainbow chard and allow to wilt. Season to taste.
Add the eggs and gently mix together. Bake in oven for about 20 mins or until the eggs have set.
For an extra touch, place under a low broil for a few mins to lightly brown the top. Be careful though, it will burn quickly if not watched!