Cooking spray or oil mister 
1 small bunch Swiss Chard, washed well
1 T butter
1 large onion, cut into thin half moons (2 cups)
1/2 t kosher salt plus more as needed
Freshly cracked black pepper
1/2 cup grated light Swiss cheese (2.5 oz.)
2 T grated Parmesan
1/2 cup white whole wheat flour
1 t baking powder
2/3 cup fat-free milk
1 t olive oil
2 large eggs beaten

Preheat oven to 400. Lightly spray a 9 inch pie plate with oil.
Separate the stems fro the leaves of the chard ( a process I find very gratifying...). Finely chop the stems. Roll up leaves and slice them into thin ribbons.
In a 10 inch skillet, melt 1/2 T of the butter over low heat. Add the onions and a pinch each of salt and black pepper.  Cook, stirring until translucent, 8-10 minutes. Increase heat to medium and cook until the onions caramelize. 8-10 more minutes. Transfer to large bowl.

Increase heat to med high, add remaining butter and chard stems. Cook, stirring until tender. 3-4 minutes.  Add the chard leaves and cook until wilted, 2-3 minutes. Season with 1/4 t of salt and pepper to taste and add them to the onions. Add the cheeses and toss well.

Sift the flour and baking powder into a medium bowl.  Whisk in the milk, olive oil, eggs, and the remaining 1/4 t salt. Pour into the bow of chard and mix well. Pour mixture into the prepared pie plate.
I served it with spinach salad with a raspberry vinaigrette and it hit the spot.