Adapted from Eats Well with Others
Makes approximately 6 side-dish servings.
1 tbsp olive oil
1 small onion, finely chopped
2 bunches swiss chard, stems and leaves cut into one-inch pieces
2 tbsp butter
2 tbsp flour
2 cups milk
2 cloves garlic, crushed
Salt and pepper, to taste
1 large sweet potato, peeled and sliced 1/8th of an inch thick
1 can white beans, drained and rinsed
1 cup coarsely shredded gruyere
Heat olive oil in heavy skillet on medium high heat. Sauté onion until translucent, 3-5 minutes. Add chard, sprinkle with salt, and cook until chard wilts and no more moisture is in the pan. Transfer to a bowl.
Add butter and flour to skillet and whisk together to form a paste. Whisk in milk, add garlic and bring to a simmer. Boil 2 minutes, whisking. Season with salt and pepper. Remove from heat.
Preheat oven to 400 degrees F. Spray a square baking dish with non-stick cooking spray. Spread half the sweet potatoes along the bottom of the dish. Top with half the beans, salt and pepper, half the greens mixture, half the cheese, and half the sauce. Add another layer of sweet potatoes, beans, greens, sauce, and top with cheese.
Cover with tin foil and bake for 45 minutes. Remove foil and bake another 15 minutes, until golden brown and bubbly. Let stand 15 minutes before serving.