Don't throw out your beet greens!! Make this beet greens and sausage gratin instead which is topped with cheesy, horseradish breadcrumbs (so good).
In a 12-inch cast-iron skillet, brown 3/4 pounds Italian sausage until just cooked through. Take sausage from pan, and sauté a thinly sliced Vidalia onion in the sausage drippings with 2 tablespoons thyme until caramelized. Add roughly chopped beet greens from 2 bunches, about 12 to 14 cups in total, a little at a time, and let sauté a few minutes until tender. Add back the sausage and stir in 2/3 cup heavy cream; let simmer a few minutes longer. Season to taste with salt and pepper. Top with a mix of 1 cup panko breadcrumbs, 3/4 cup shredded extra-sharp cheddar, 2 tablespoons grated fresh horseradish, and 2 tablespoons olive oil. Bake at 400 degrees for about 25 minutes until topping is browned and cream is bubbling around the edges.