Step 1

For the meatballs: Preheat the oven to 450º with the oven rack in the upper third of oven. Line a rimmed baking sheet with heavy duty aluminum foil.

Step 2

Mix together the beef, sausage, parmesan, parsley, egg, garlic, panko, salt, and pepper in a medium bowl until well combined. Form the mixture into about 40 (1/2-inch wide) meatballs. Lightly spray the baking sheet with nonstick spray and arrange the meatballs in a single layer.

Step 3

Bake the meatballs for 6 to 8 minutes or until they are firm to the touch. Increase the heat to broil. Broil the meatballs for 2 to 4 minutes or until browned. Set aside.

Step 4

For the soup: Heat the oil in a large stockpot or Dutch oven over medium-high heat. Add the carrots, onion, and celery, and cook for 4 minutes or until the vegetables start to soften. Add the garlic and cook, stirring, for 1 minute.

Step 5

Gradually stir in the salt, pepper, chicken broth, and beef broth. Bring to a boil. Reduce heat to a gentle simmer, and add the couscous. Cover and cook 8 minutes or until the couscous is just tender.

Step 6

Add the spinach and cook for 1 minute, until just wilted. Stir in the meatballs and cook 2 minutes or until the meatballs are warmed throughout. Remove the pot from the heat and stir in the lemon juice.

Step 7

Serve the soup in bowls, and garnish with additional parmesan cheese, chopped parsley, and black pepper.