Hot sandwiches with cheese, spinach and ricotta

Ingredients:

• 1 tbsp extra-virgin olive oil
• 150 g of small spinach
• 0.5 cup ricotta
• 1 tbsp. grated mozzarella
• 0.5 tbsp. freshly grated parmesan
• 8 slices of strong white bread, 0.8 cm thick.
• 4 tablespoons unsalted butter at room temperature

Preparation:

1. Heat a large skillet over medium-high heat. Add olive oil, spinach, and 0.5 teaspoon salt. Sauté until the spinach is completely wilted. Transfer the spinach to a sieve set over a bowl. Let cool to room temperature. When the spinach is cool enough to handle, squeeze out as much liquid as possible.
2. Coarsely chop the spinach and place it in a medium bowl. Add the ricotta, mozzarella, Parmesan, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Stir and set aside.
3. Place the bread slices on a clean work surface. Brush one side of each slice with butter.
4. Heat a large skillet over medium heat. Place 4 slices of bread in the skillet, butter side down. Spread about 1/3 cup of the spinach and cheese mixture on each slice. Spread evenly to cover the entire surface of the bread, then top with the remaining slices, butter side up. Cook until golden brown, 2-3 minutes. Carefully flip the sandwiches and cook until the bread is toasted on the other side and the cheese is melted, another 2-3 minutes.
5. Transfer the sandwiches to a clean work surface and let them cool for 1 minute. Cut in half diagonally.