Clean collard greens and remove stems by folding each leaf in half and cutting out center rib. Stack all leaves and cut lengthwise into strips about 1-1/2" in width then cut into 1/4" ribbons.

In a large pot or skillet, cook onion and garlic with crushed red pepper flakes over medium heat until translucent, about 3 minutes. Stir greens into pan with 1/4 cup water and oregano. Cover and cook for about 2 minutes until greens are wilted but still green. Season with honey, vinegar, salt and pepper to taste.