Meatloaf

Heat the oven to 350F (175C)

Line a rimmed sheet pan with foil and set a rack in the middle of the oven.

Soak the breadcrumbs

Stir the breadcrumbs and milk together in a large bowl and leave them 5 minutes, until the crumbs are saturated and pasty. This panade is what keeps the loaf tender, because the wet starch blocks the beef proteins from squeezing together into a dense brick as they cook.

Mix the meat

Add the egg, grated onion, garlic, Worcestershire, salt, pepper, and parsley to the panade and stir until even. Add the beef and mix with a hand only until no streaks of plain meat remain, about 30 seconds. Overworking makes the texture springy and tight.

Shape it free form

Turn the meat onto the lined pan and pat it into a loaf about 9 inches long, 5 inches wide, and 2 1/2 inches tall. Smooth the top and square the ends. A sheet pan beats a loaf pan here, since the rendered fat runs off instead of pooling and all four sides brown rather than steam.

Bake and glaze

Bake 40 minutes. Whisk the ketchup, brown sugar, and vinegar together and brush the mixture over the top and sides. Return the loaf to the oven for 15 to 25 minutes more. It is done when an instant-read thermometer pushed into the center reads 160F (71C), which is the safe temperature for ground beef. Total time runs 55 to 65 minutes.

Rest before slicing

Move the loaf to a board and wait 10 minutes. Cutting it straight out of the oven spills the juices onto the board and leaves the slices dry and crumbly. Cut 1 inch slices with a serrated knife.