Preheat the oven to 200°C (400°F). Trim the bases and remove any damaged leaves from the Belgian Endives[3603].
In a large saucepan combine Water[117], a knob of Butter[40], Lemon Juice[516], Sugar[886] and a pinch of Salt[695]; bring to a gentle simmer. Add the prepared endives, cover and poach over low heat until tender when pierced, about 20–25 minutes. Drain well and pat dry, pressing gently to remove excess liquid.
Wrap each cooled endive in a slice of Cooked Ham[5409] and arrange seam-side down in a buttered baking dish.
Make the béchamel: melt a couple of tablespoons of butter in a saucepan, stir in the All-Purpose Flour[595] to form a smooth roux and cook for 1–2 minutes without browning. Gradually whisk in warm Whole Milk[567] until the sauce is thick and smooth.
Season the béchamel with a little Salt (to taste), White Pepper[1116] and a grating of Nutmeg[462]. If it seems too thick, loosen with a splash more milk.
Pour the béchamel evenly over the ham-wrapped endives, sprinkle generously with grated Gruyère[5514] and dot with a little extra butter if you like. Bake until the top is bubbling and golden, about 15–20 minutes. Let rest a few minutes before serving.
