Frango Divan

Heat the oven to 190 C (375 F) and butter a 23 x 33 cm (9 x 13 inch) baking dish. Bring a large pot of water to a boil with half the salt, drop in the broccoli florets, and cook just 2 minutes; they should still be bright green with a little snap. Drain in a colander, rinse briefly under cold water to stop the cooking, then spread on a clean towel and pat thoroughly dry.

Return the pot to the stove with fresh water and the remaining salt and bring to a bare simmer. Add the chicken breasts, adjust the heat so the water barely bubbles, and poach 12 to 15 minutes, until an instant-read thermometer hits 74 C (165 F) in the thickest part. Transfer to a cutting board and, when cool enough to handle, shred or cube into bite-size pieces. (If using rotisserie chicken, skip this step and start the sauce.)

In a large saucepan over medium heat, melt the butter and cook the garlic for 30 seconds, until fragrant. Whisk in the flour and cook 1 minute to lose the raw taste. Gradually whisk in the broth, then the milk, whisking out any lumps as you go. Simmer, whisking often, for 4 to 5 minutes, until the sauce thickens enough to coat the back of a spoon.

Pull the pan off the heat and stir in the cheddar and Parmesan a handful at a time until smooth. Stir in the sherry, Dijon, curry powder, salt, and pepper. Taste; the sauce should be slightly saltier than seems right on its own, because the chicken and broccoli will dilute it.

Scatter the broccoli evenly over the bottom of the buttered dish and layer the chicken on top. Pour the sauce over everything and nudge it into the gaps with a spatula so every floret is coated.

Toss the panko with the melted butter until evenly coated, then mix in the remaining cheddar. Sprinkle the topping over the casserole and bake on the middle rack for 25 to 30 minutes, until the edges bubble and the crumbs are deep golden. If the topping browns before the filling bubbles, tent loosely with foil.

Let the casserole stand 10 minutes before serving; the sauce thickens as it cools so each scoop holds together instead of running. Serve hot over rice, noodles, or on its own with bread.