- In a large dutch oven over medium-high heat, cook bacon until crispy. Drain fat and return to pan. Add onion and sweat until translucent. Add collard greens and sauté until bright green. Pour in stock and reduce to a simmer.
- While greens are cooking, melt ½ pound butter in a saucepot over medium-high heat until frothy, then whisk in flour to make a roux. Whisk in milk, cream, nutmeg, and cayenne and bring to a boil (the mixture will be quite thick). Add the béchamel to the greens and incorporate fully. Continue to simmer until tender, about 15 to 20 minutes.
- In sauté pan over high heat, melt remaining butter. Add panko and benne seeds and cook, stirring constantly, until evenly golden brown. Season with salt to taste. When the greens are tender, season with salt and pepper to taste, transfer to a serving dish, and top with the breadcrumb mixture. Serve immediately.