In a small bowl, combine the ricotta cheese with a pinch of salt, black pepper, and any optional seasonings. Stir until smooth and creamy.

Spread the ricotta mixture over one side of each slice of bread. Layer one slice with sun-dried tomatoes, spinach, and mozzarella or provolone. Top with the other slice, ricotta side facing the filling.

Heat a skillet over medium heat with butter or olive oil. Place the sandwich in the skillet and grill for about 4-5 minutes until golden brown and cheese begins to melt.

Flip the sandwich and cook for an additional 4-5 minutes until the other side is golden and crisp.

Remove the sandwich from the skillet, let it cool for a minute, then cut diagonally and serve warm.