Make Oven Porcupine Meatballs Recipe: tender beef and rice meatballs baked in a sweet-tangy tomato sauce. Easy, comforting weeknight meal.
Preheat the oven to 350°F (175°C). This first step gets the environment ready so the meatballs will bake evenly; while the oven comes to temperature you can move straight into assembling the mixture so nothing cools down and the rice begins to soften just a bit once exposed to moisture in the mixture.
In a large bowl, gently combine the ground beef, long-grain rice, finely chopped onion and green bell pepper, the beaten egg, salt, and black pepper. Use your hands or a spoon to fold everything until uniformly distributed but avoid overworking the meat — you want a tender texture and rice grains visible throughout the mixture, not a dense paste.
Form the mixture into roughly 1-inch meatballs and place them in a single, tight grid inside a rectangular 9x13-inch baking dish, leaving small gaps for sauce to settle. Keep the same mixing bowl nearby with a spoon or spatula resting on its rim — a quiet clue of the action that produced these neat, rice-speckled spheres.
In a separate small bowl, combine the tomato sauce and diced tomatoes with the brown sugar, Worcestershire sauce, dried oregano, and garlic powder. Stir until the sugar dissolves and the aromatics marry into a thick, glossy red sauce dotted with tiny herb flecks.
Pour the prepared tomato sauce evenly over the arranged meatballs so each ball is generously coated and the sauce pools between them, accentuating the rice-speckled texture. The tray should now read as a cohesive unbaked casserole with glossy red sauce and visible grainy textures on each raw meatball.

Carefully pour about a cup of water into the empty channels around the edges of the baking dish (keeping water off the tops of the meatballs) so the assembled dish retains moisture while baking — this will steam the rice inside the meatballs and keep the sauce from reducing too aggressively.
Cover the baking dish tightly with aluminum foil so the interior traps steam and cooks the rice through without drying the meatballs. Tuck the foil edges to the rim of the rectangular dish for an even, sealed environment.
Bake the covered dish for about an hour, then remove the foil for the last ten minutes to allow the tops of the meatballs to brown lightly and the sauce to become slightly thicker and glossy. The finished meatballs should show gentle browning and bubbling sauce around them while the rice inside the meatballs is fully tender.
Let the baking dish rest for a few minutes out of the oven, then serve the meatballs hot directly from the same rectangular cream-colored dish — the rice-speckled, browned meatballs nestled in a rich, glistening tomato sauce dotted with fresh herb flecks make a comforting, homey presentation.
