1. Using your hands, crush the tomatoes into a slow cooker and
add their juices. Add the olive oil, tomato paste, basil sprig,
crushed red pepper and half of the garlic. Cover and cook on high
for 3 hours, until the tomato sauce is very flavorful.
2. Meanwhile, in a large bowl, mix the ground chuck with the
remaining garlic and the bread crumbs, egg, 3 tablespoons of
Parmigiano-Reggiano, 1 tablespoon of kosher salt and 1/2
teaspoon of pepper. Roll the mixture into 18 meatballs, being
careful not to pack them too firmly.
3. Add the meatballs to the sauce. Cover and cook on high for 1
hour longer, until no trace of pink remains in the center of the
meatballs. Discard the basil sprig. Add 1 tablespoon of the sliced
basil to the sauce and season with salt and pepper. Spoon the
meatballs into bowls, sprinkle with the remaining 1 tablespoon of
sliced basil and serve, passing grated cheese at the table.
—Melissa Rubel Jacobson
MAKE AHEAD The cooked meatballs can be refrigerated in the
sauce for up to 2 days before serving.