01 - Heat olive oil in a large skillet over medium heat. Add diced onion and sauté until translucent, about 5 minutes.
02 - Stir in minced garlic and cook for an additional 1 minute until fragrant.
03 - Add the chopped winter greens to the skillet. Stir to combine and allow to wilt slightly, about 3 minutes.
04 - Pour in vegetable broth, then season with salt, pepper, and red pepper flakes if using. Stir well.
05 - Reduce heat to low, cover, and let the greens braise gently for 15 to 20 minutes until tender.
06 - Remove lid, adjust seasoning to taste, and serve warm.