Place olives in a pot with a lemon slice and cover with water. Bring to a boil and simmer for 1½ hours, changing the water every 30 minutes. Drain.
In a large bowl, combine beef, parsley, onion, paprika, salt, ras el hanout, matzo meal, and olive oil. Mix until just combined. Form into medium meatballs.
Heat olive oil in a wide heavy pot over medium heat. Add garlic and paprika and cook until fragrant, about 2 minutes. Stir in tomato paste and cook 1 minute more.
Add water and olives. Bring to a simmer.
Add meatballs in a single layer. Add water as needed to come halfway up the meatballs. Cover partially and simmer until sauce thickens and meatballs are cooked through, 30 to 40 minutes.
Finish with parsley and serve warm.