• 4 tablespoons unsalted butter, plus more for toast
• 1/4 cup unbleached all-purpose flour
• 3 cups whole milk
• Kosher salt and freshly ground pepper
• 6 peeled hard-boiled eggs
• 6 slices white sandwich bread
• Chopped chives and smoked paprika, for serving
1. Melt butter in a medium saucepan over medium-high heat. Add flour; whisk until nutty and golden, 1 to 2 minutes. Whisk in milk; bring to a gentle boil, whisking constantly, until mixture thickens to consistency of gravy, 4 to 5 minutes. Remove from heat, season with salt and pepper, and cover to keep warm.
2. Cut eggs in half. Remove yolks and press through a medium-mesh sieve, or mince them. Chop whites; stir into bechamel. Toast and butter bread. Divide bechamel mixture evenly among toasts; sprinkle evenly with yolks. Top with chives, paprika, and pepper. Serve immediately.