Preheat oven to high broil (550°F.) Line a large sheet pan with foil, spray with cooking spray, and set aside.
In a large bowl, combine ground beef, uncooked white rice, grated onion, minced garlic, large egg, salt, Italian seasoning, pepper, and dried basil. Knead the mixture until just combined, avoiding overmixing (which makes the meatballs dense).
Form meatballs by measuring out 1 and 1/2 tablespoons per meatball and tightly squishing the mixture together until a firm meatball is formed. Repeat until all the mixture is used. The mixture should make around 22–25 meatballs.
Place all the formed meatballs on the prepared tray, generously spritz with cooking spray, and broil in the oven for 3 minutes per side (6 minutes total). This helps them to not break apart in the slow cooker. Remove from oven and set aside.
Spray the slow cooker with cooking spray. Add in beef stock/broth, tomato sauce, brown sugar, and Worcestershire sauce. Stir.
Layer the meatballs on top of the tomato mixture. Gently spoon the sauce over.
Cover and cook on low for 5–7 hours, high for 3–5 hours, or until rice is tender and meat is cooked through (165°F). I recommend cooking on low; my slow cooker takes 6 hours. Avoid checking too often; when a slow cooker's lid is removed, it takes a while for everything to get back to temperature.
Taste meatballs and sauce and add any additional salt/pepper as needed. Gently spoon out meatballs and sauce from the slow cooker and serve over cooked rice(see note 1). Garnish with fresh parsley if desired and enjoy!
Video
Notes
Note 1: I love serving these meatballs over cooked basmati rice. Here’s a quick breakdown of the process:
Measure the rice and rinse it in a fine-mesh sieve until the water runs clear.
Place rice in a bowl and cover with water to soak for 5–10 minutes.
While rice is soaking, fill a large pot with water and bring to a boil.
Once water is at a rolling boil, drain the rice and add it to the pot.
Cook, without reducing the heat, for 5 minutes (taste and test to make sure it is tender; if not, add another 1–2 minutes), and drain and fluff with a fork.
Storage: Store in an airtight container in the fridge for up to 3 days or freeze for up to 3 months. Thaw overnight in the fridge before reheating.