This is an open-faced sandwich built on thick bread, sliced turkey, crispy bacon, and a quick Parmesan Mornay sauce that goes under the broiler until bubbly. The whole thing comes together in 30 minutes, which makes it a genuinely useful option on a weeknight when you have leftover roasted turkey and want something more satisfying than a cold sandwich.
Substitutions that actually work
- Turkey: Deli-sliced turkey breast works fine here — pile it on thick. Rotisserie chicken is a solid swap if that’s what you have.
- Bread: Texas toast or sourdough hold up best under the sauce. Sandwich bread will get soggy fast, so avoid it.
- Whole milk: 2% milk works in the Mornay sauce. Avoid skim — the sauce won’t thicken as cleanly and the flavor falls flat.
- Parmesan: Pre-grated Parmesan from a bag melts unevenly and can make the sauce grainy. Buy a small wedge and grate it yourself — it takes two minutes and makes a real difference.
- Bacon: Cook it ahead or use pre-cooked strips to keep the timeline tight. Turkey bacon works if needed, though the flavor is milder.
The technique that matters
The Mornay sauce is the one place where rushing costs you. Once you add the milk to the roux, keep whisking and don’t walk away — the sauce can go from smooth to lumpy in under a minute if the heat is too high or you stop stirring. Bring it to a gentle simmer, not a rolling boil, and give it the full three minutes to thicken before you add the Parmesan. Adding cheese to a sauce that isn’t fully thickened yet is the main reason the sauce ends up thin and watery on the plate. Get the consistency right on the stovetop, and the broiler finish takes care of everything else.
Mistakes to avoid
- Skipping the oven preheat: The oven needs to be fully up to temperature before the sandwiches go in. A cold oven means the sauce heats unevenly and the bread steams instead of crisping at the edges.
- Overloading the sauce: More sauce does not mean better results. Too thick a layer and the center stays cold and loose while the edges brown. A generous but even spoon-over is enough.
- Wet tomatoes: Slice your tomatoes and blot them dry with a paper towel before placing them on top. Excess moisture thins the sauce during baking and makes the bread soggy underneath.
- Crowding the baking sheet: Leave a little space between sandwiches so heat circulates. Packed too close, the edges don’t brown and the sauce doesn’t set properly.
- Letting it sit before serving: This dish does not hold well. The sauce tightens and the bread softens as it cools. Plate it straight from the oven — skip the garnish, it’s not worth the extra dish.
Make-ahead notes
The Mornay sauce is the only component worth making ahead. It keeps in the fridge for up to three days in a sealed container. Reheat it gently in a small saucepan over low heat, whisking in a splash of milk to loosen it back to a pourable consistency before spooning it over the turkey. The bacon can be cooked a day ahead and stored in the fridge — just lay it on top cold and the oven will warm it through. Don’t assemble the full sandwiches in advance; once the sauce hits the bread, the texture degrades quickly and there’s no recovering it.
Kentucky Hot Brown Sandwich
Ingredients
- 8 slices thick-cut white bread such as Texas toast or sourdough
- 1.1 lbs roasted turkey breast sliced
- 1 cup ripe tomatoes sliced
- 8 slices crispy cooked bacon
- 2 tablespoons unsalted butter
- 2 tablespoons all-purpose flour
- 1 ½ cups whole milk
- ½ cup Parmesan cheese freshly grated
- 1 teaspoon salt
- ½ teaspoon white pepper
- 1 pinch nutmeg freshly grated
Instructions
- Preheat your oven to 200°C (390°F).
- In a medium saucepan over medium heat, melt the butter until foaming. Add flour, whisking constantly for 1 minute to create a smooth roux.
- Gradually whisk in the milk, ensuring no lumps, and bring to a simmer. Cook until the sauce thickens to coat the back of a spoon, about 3 minutes.
- Stir in the Parmesan cheese, salt, white pepper, and nutmeg until smooth. Remove from heat and set the Mornay sauce aside.
- Place the slices of bread on a baking sheet. Evenly divide and layer the turkey slices on each piece of bread.
- Spoon Mornay sauce generously over the turkey, ensuring coverage. Top each with two slices of tomato and two slices of bacon.
- Place the baking sheet in the oven and bake for 10 minutes or until the cheese sauce is bubbly and golden brown.
- Serve hot, accompanied by a simple green salad and a chilled glass of iced tea or lemonade.
Notes
Nutrition
Frequently asked questions
Can I use leftover Thanksgiving turkey for this?
Yes, and it’s one of the best uses for it. Slice it about a quarter-inch thick so it doesn’t dry out under the broiler, and make sure it’s fully thawed and at room temperature before assembling so the sandwich heats evenly.
My Mornay sauce turned out lumpy — what went wrong?
The most common cause is adding cold milk too fast to the roux. Add the milk gradually while whisking constantly, and make sure the milk isn’t straight from the fridge — room temperature or slightly warmed milk incorporates much more smoothly.
Can I use the broiler instead of baking at 200°C?
Yes, and it’s actually faster — about 3 to 4 minutes under a hot broiler will bubble and brown the sauce. Watch it closely the entire time because it can go from golden to burnt in under a minute.
Is there a way to make this work for two people instead of four?
Halve all the ingredients straightforwardly — the sauce recipe scales down without any issues. Make the full sauce anyway if you want leftovers, since it reheats well and works on pasta or vegetables later in the week.
What’s the best way to keep the bread from getting soggy?
Toast the bread lightly before assembling — just a minute or two in the toaster or a dry skillet creates a barrier that slows moisture absorption. This is especially important if your turkey or tomatoes are on the wetter side.
If you liked this one
- Classic Southern Ham Salad
- Diner-Style Patty Melt
- Southern Stovetop Creamed Corn
- Easy Silky Brown Gravy