6-8slicesof mozzarella cheesedepending on how many meatballs you make
basil for servingif desired
Add 1 tablespoon of oil to a large skillet and heat.
Toss in onion and cook until tender and caramelized, 3-4 minutes.
Add in garlic and cook for 1 minute.
Add the onion and garlic mixture to a large bowl along with ground beef, breadcrumbs, cheese, egg and parsley. Mix with your hands or with a spoon until combined. Roll into meatballs. (I rolled them into 6 large meatballs, You can do 8 meatballs to feed two sliders per person.)
Add the remaining 1 tablespoon of oil to the same skillet the onion was cooked in. Once the pan is nice and hot add the meatballs and brown on both sides. (about 1-2 minutes on each side).
Leave the meatballs in the pan and pour tomato sauce on top. Bring to a simmer and cook for 15 minutes.
To serve place 1 meatball on the bottom of a slider. Top with 1 slice of mozzarella cheese. Place under the broiler on high until cheese has fully melted and starts to brown. Top with fresh basil if desired and the top of the slider bun.