Place the fava beans in a pot and cover with water up to 1/2 inch above the fava beans. Salt to taste and let the fava beans soak overnight.
The next day, as some of the water will have been absorbed by the fava beans, add a bit more water to cover the fava beans completely.
Cover the pot and start to cook at very low heat. It is important that while the fava beans are cooking you do not stir them until they are completely cooked, otherwise they will stick to the bottom of the pot.
They will cook for about 2 hours. The fava beans will turn into a puree. While they are boiling, if you notice that the water level has lowered, add some boiling water.
Clean and wash the swiss chard several times. You want to separate the stems from the green part. Slice the stems in two or three slices as they may be thick and take longer to cook.
Bring water to boil in a large pot and first add the stems. Let them cook for 3 minutes and then add the green leaves. Continue to cook for another 5-6 minutes and remove them from the water. Leave about two cups of water in the cooked vegetables.
In a saute` pan add 1 cup of EV olive oil and the red onion sliced in thin slices. Let the onion caramelize.
Serve the swiss chard with a large spoonful of fava beans topped by caramelized onions and some of the oil from the onions.