1 large bunch Swiss chard, spinach, kale, bok choy leaves, turnip greens, beet greens, collards (1 to 1 1/4 pounds)
1/4 cup unsalted butter
1/4 cup all-purpose flour
1 onion, finely chopped
3 cloves of garlic, minced
1 to 1 1/4 cups whole milk
Salt and freshly ground black pepper
Pinch of freshly grated nutmeg
Pinch of crushed red pepper flakes
2 T grated hard cheese
1Trim the tough inner ribs from the Swiss chard leaves and save them for another use. Roughly chop the leaves.
2Bring a medium-sized pot with 1 inch of salted water to a boil, and cook the chard in two batches, stirring constantly, until wilted, 1 to 2 minutes. Drain the leaves in a colander and rinse under cold running water until cool. Squeeze the chard a small handful at a time to remove as much moisture as possible.
3In a medium-sized pot over medium heat, melt the butter. Whisk in the flour and cook for a couple of minutes until light golden. Add the onion and cook until it is translucent, 2 to 3 minutes, then add the garlic and cook until fragrant, about 30 seconds.
4Pour in 1 cup of the milk, whisking constantly, and cook until the mixture thickens into a sauce, about 5 minutes. Season with salt, pepper, the nutmeg, and the crushed red pepper flakes. If the sauce is too thick, add the remaining 1/4 cup of milk, whisking it until you reach the desired thickness.
5Add the wilted chard, stirring gently to combine.
6Sprinkle with the cheese and serve immediately.