The Food Lab's All-American Meatloaf

Ingredients

• 1/2 cup homemade or store-bought low-sodium chicken stock
• 1/4 cup buttermilk
• 1/2 ounce unflavored gelatin
• 2 slices high-quality white sandwich bread, crusts removed and torn into rough pieces
• 4 ounces button or cremini mushrooms, cleaned
• 3 anchovy filets
• 1/2 teaspoon Marmite
• 2 teaspoons soy sauce
• 1 teaspoon paprika
• 2 medium cloves garlic, roughly chopped
• 1 small onion, roughly chopped
• 1 small carrot, peeled and roughly
• 1 stalk celery, roughly chopped
• 2 tablespoons unsalted butter
• 12 ounces freshly ground pork
• 1 1/4 pounds freshly ground beef
• 2 large eggs
• 4 ounces cheddar, provolone, Monterey Jack, or Muenster cheese, finely grated
• 1/4 cup finely minced fresh parsley
• Kosher salt and freshly ground black pepper
• For the glaze:
• 3/4 cup ketchup
• 1/4 cup packed light brown sugar
• 1/2 cup cider vinegar
• 1/2 teaspoon freshly ground black pepper

Directions

1. Pour the chicken stock and buttermilk into a liquid measuring cup, then scatter the gelatin across the surface and leave it to hydrate. In a food processor, chop the bread and mushrooms with short pulses until they are very fine. Scrape that mixture into a large bowl and keep it nearby.
2. Put the anchovies, Marmite, soy sauce, paprika, and garlic in the food processor, and pulse until you have a smooth, concentrated paste, stopping to scrape the bowl when needed. Add the onion, carrot, and celery, then pulse again until the vegetables are minced small but have not turned into puree.
3. Melt the butter in a 10-inch nonstick skillet set over medium-high heat, letting it foam before adding the chopped vegetable mixture. Cook, stirring and tossing often, until the vegetables have softened, the moisture has mostly cooked away, and the mixture has begun to take on a little color, about 5 minutes. Pour in the buttermilk mixture, bring it to a simmer, and continue cooking until the liquid is reduced by half, about 10 minutes. Add everything from the skillet to the bowl with the bread and mushrooms, mix it well, and let it sit until it is comfortable to handle, about 10 minutes.
4. Add the meat mixture, eggs, cheese, parsley, 1 tablespoon salt, and 1 teaspoon pepper to the bowl. Using clean hands, combine everything gently but thoroughly, until the mixture looks even throughout; it should feel fairly loose. Pinch off a teaspoon-sized sample, set it on a microwave-safe plate, and cook it on high power until done, about 15 seconds. Taste that cooked sample, then season the remaining mixture with additional salt and/or pepper if needed.
5. Pack the mixture into a 9- by 5-inch loaf pan, taking care to press it in so air pockets are not left at the bottom. Depending on your pan’s capacity, you may have some extra mix; cook that in a ramekin or shape it free-form beside the loaf. Pull off a piece of heavy-duty aluminum foil big enough to line a rimmed baking sheet, then cover the loaf pan tightly with it and crimp the foil around the pan’s edges. Chill the meatloaf while the oven heats. The meatloaf can be refrigerated for up to 2 days.
6. Set an oven rack in the lower-middle position and heat the oven to 350 degrees F. Once the oven is ready, take the loaf from the refrigerator and, keeping the foil in place, carefully turn it out onto the rimmed baking sheet. Open up the foil and flatten it, but leave the pan sitting over the meatloaf. Turn the foil edges upward so any juices released during baking stay contained. Bake until the loaf is just starting to set and the surface feels firm when touched, about 30 minutes.
7. Slide a thin metal spatula under one edge of the upside-down loaf pan, nudging until the pan releases cleanly from the meatloaf. With oven mitts or a folded kitchen towel, lift off the pan so the meatloaf remains centered on the foil. Put it back in the oven and continue baking until an instant-read thermometer inserted in the middle reads 140 degrees F, about 40 minutes longer. A generous amount of juice may collect on the foil, and that is fine. Take the meatloaf out of the oven and let it rest for 15 minutes. Raise the oven temperature to 500 degrees F.
8. While the meatloaf rests, prepare the glaze. In a small saucepan, whisk together the ketchup, brown sugar, vinegar, and pepper over medium-high heat, cooking until the sugar has dissolved and the sauce is smooth, about 2 minutes. Take the pan off the heat.
9. Brush the meatloaf with a thin, even coating of glaze, then place it back in the oven for 3 minutes. Brush on another layer and bake for 3 minutes more. Add a final coating of glaze and bake until it bubbles and turns a dark, glossy brown, about 4 minutes longer. Remove the meatloaf from the oven and let it rest for 15 minutes. Slice and serve with any remaining glaze and mustard or ketchup as desired.