Preheat the oven to 375F

Spray the baking pan with cooking spray

Crack the egg into the mixing bowl

Lightly beat the egg

Cut the onion in half

Cut off the top and bottom of the onion

Remove the outer layer or two of skin from the onion

Turn the onion cut-side down on the cutting board

Cut the onion from one side to the other into several very thin slices (the thicker the slices, the larger the chopped pieces)

Cut the onion the other direction (from side to side) into several thin slices

Add the onion to the mixing bowl

Add the milk, breadcrumbs, pepper, and garlic to the mixing bowl

Stir the ingredients until they are blended

Add the ground beef to the mixing bowl

Using your hands (yeah I know...ewwww check out the note) mix the ingredients until everything is blended

Scoop out a small handful of the mixture

Roll the mixture into a ball, pressing tighly as you roll it

Aim for a ball about the twice size of a golfball

Compress the golfball (not goofball...that's your spouse!) into a patty rather than a ball

Put the patty onto the sprayed baking pan

Repeat for the rest of the mixture

Put the baking pan into the preheated oven

Bake for 20 minutes

Remove the baking pan from the oven

Arrange the bottoms of the slider buns on the serving tray

Put one patty onto each slider bun

Put the tops of the buns onto the patties (you do remember which slider top goes on each bottom, don't you? If not I won't tell but don't make that mistake next time. Seriously this is a great way to stress your poor kids out by asking that question when making these with them.)