Preheat the oven to 200°C.

In a large, oven-proof skillet, heat the olive oil over medium-high heat. Add the onion and leek and cook until soft. Add the spinach and cook for about 2 minutes, until it starts to wilt. Stir in the minced garlic and cook until fragrant. Add the tomato paste and cook for 1 minute, stirring frequently.

Pour in the passata, beans, Italian seasoning, lemon juice, vinegar, salt and pepper. Bring to a boil, reduce the heat and cook for 8-10 minutes, stirring occasionally.

Stir in the fresh herbs, 1 cup of the mozzarella and ¼ cup of the parmesan cheese. Evenly sprinkle the top with the remaining cheeses. Add the cherry tomatoes as desired to the top (if using).

Place in the preheated oven and cook for 10 to 15 minutes, until the sides are bubbling and the cheese turns golden.

Serve with rustic bread!