Soak 2 slices of bread (torn into little pieces) in 1/2 C whole milk for 5 minutes.
Gently mix bread & milk with 8 oz ground beef, 8 oz ground pork & 4 oz ground veal with a wooden spoon or gloved hand (you can even use plastic wrap or a Ziploc baggie).
Mix in 1/2 C finely grated Romano or Parmesan cheese, 3 T coarsely chopped fresh parsley, 1 minced clove garlic, 1 egg & 1 t salt.
Refrigerate for at least 30 minutes.
Heat 1 jar or large can of spaghetti or pasta sauce in a large skillet over medium heat.
Roll meat mixture (with gloved hands) into 1 oz balls and place in skillet.
Bring to a gentle simmer. Cook, partially covered, until meatballs are cooked through. About 20-25 minutes.
Preheat oven to 400 degrees.
You'll need: 2 dozen brioche rolls or slider buns, 1 1/2 C coarsely grated mozzarella, 1/2 C finely grated Romano or Parmesan & coarsely shredded basil leaves.
Working in batches, arrange rolls/buns , cut side up on a baking sheet or pizza stone.
Place 1 meatball, a spoonful of sauce, 1 T mozzarella & 1 t Romano on bottom halves.
Bake until cheese melts...3-4 minutes.
Remove from oven.
Top with basil leaves & top part of bun/roll.