Heat up the widest skillet you have over medium low heat, and add the olive oil and sliced onions. Cook for 20 minutes, stirring occasionally, until the onions have caramelized. If at any point the onions are browning instead of turning translucent, turn the heat down slightly.
Toast the bread by placing the slices on a sheet pan and sticking them under the broiler for a minute or so on each side. Don’t walk away from it, it burns quickly! Remove the bread from the oven and preheat the oven to 350 degrees F. Rub the bread with the garlic cloves.
Pile on a 1/4 cup or so of the pulled pork, then add about a tablespoon of the caramelized onions. Sprinkle with mozzarella cheese, and pop it into the oven until the cheese has melted. Enjoy!