4 slices bacon
1 medium onion, chopped
6 cups finely chopped kale (or broccoli)
1/2 tsp red pepper flakes
1 qt (4 cups) chicken stock, homemade or low-sodium store-bought
1/2 cup shredded cheese (I use low-fat six-cheese Italian blend)
1/4 cup half-and-half (not fat-free)
Kosher salt and fresh black pepper, to taste
1 sheet of puff pastry, defrosted according to package directions
In a 5-quart Dutch oven or heavy stock pot, cook the bacon over low-medium heat until the bacon is brown but not crisp. With a slotted spoon, remove the bacon and set aside.
Add the onion, and cook for 2-3 minutes, until translucent. Stir in the kale and red pepper flakes, and cook, stirring occasionally, for 2 minutes, until the kale wilts slightly. Pour in the chicken stock.
Bring the soup to the boil over high heat; then, reduce the heat to simmer, cover the pot, and cook for 20 minutes.
While the soup is simmering, preheat the oven to 425°F.
Roll the puff pastry out on a lightly floured countertop, and cut with a sharp knife into 1-1/2 inch squares. Place the pastry squares on a rimmed baking sheet. Bake at 425F for 10-12 minutes, until lightly crisp. Remove from the oven and set aside.
Use an immersion blender to puree the soup, or puree in batches in a stand blender, and return the soup to the pot. Stir in the cheese and half-and-half, and continue cooking over low heat for 4-5 minutes, until the cheese melts.
Chop the bacon and return it to the pot. Taste, and season as needed with salt and pepper.
Serve hot, garnished with the puff pastry croutons, or allow to cool completely and freeze in airtight containers.