1. Preheat the oven to 350 degrees Fahrenheit.
2. Mix ground beef, eggs, and matzo meal until combined, then form into balls. Place on a metal baking sheet and cook in the oven for 20 minutes.
3. In a wide, shallow pot, combine three cups water, brown sugar, soy sauce, ketchup, vinegar, lemon juice, and salt and bring to a simmer. In a separate bowl, mix cornstarch with hot water until dissolved, then add to sauce and mix to combine. Bring sauce to a boil, then reduce heat to low. Add meatballs and simmer for 40 minutes.
4. Serve over rice.