A favorite at our house.

I sometimes use frozen meatballs when I don't have time but I use this meatball recipe when I do.
I sometimes buy baguettes when I don't have time but I try to make my own in the break maker.  I'll post that recipe soon.

2 slices white sandwich bread, cut into little pieces
1/2 cup plain bread crumbs
2 pounds ground sirloin
1/2 cup Parmesan cheese
1 tsp parsley
2 tsp Kosher salt
1/2 medium onion, diced
1/2 cup milk
2 large beaten eggs
olive oil
1 jar of pasta sauce
baguettes or sub buns
mozzarella cheese

Place first 8 ingredients in a bowl and mix well.  (Yes, you'll have to use your hands to really mix it all together well.)
Form into 1" balls, refrigerate for about 15 minutes to ensure firmness and so they won't break apart while browning.
Pour olive oil into a frying pan, heat till medium, and brown meatballs on all sides.
Turn as needed till all sides are brown.
Place meatballs in sauce and cook until done inside, at simmer, for about 2-4 hours.
Remove each meatball and place cooked meatballs on baguettes, topping with extra sauce as you go.
Sprinkle mozzarella cheese on top of each meatball sub, and warm in oven until cheese is bubbly and bread is warmed.
I cut the baguettes into preferred serving size.