Bring a large pot of salted water to a boil. Add the pasta shells and cook until just al dente, about 10 minutes. Drain and set aside to cool slightly.
While the pasta cooks, heat olive oil in a skillet over medium heat. Add minced garlic and cook until fragrant, about 30 seconds, releasing a warm, savory aroma.
Add chopped fresh spinach to the skillet and sauté until wilted, about 2-3 minutes, until the greens turn vibrant and tender. Remove from heat and let cool slightly.
In a mixing bowl, combine ricotta, grated Parmesan, chopped herbs, and sautéed spinach. Season with salt and pepper, mixing until smooth and well blended.
Use a small spoon or scoop to carefully stuff each cooked shell with the ricotta and spinach mixture, pressing gently to fill without tearing the shell.
Arrange the stuffed shells in a baking dish in a single layer, seam side down. If desired, pour marinara sauce over the shells, spreading evenly.
Sprinkle shredded mozzarella cheese generously over the top of the shells and sauce. Cover the dish with aluminum foil to trap moisture.
Bake in a preheated oven at 180°C (350°F) for 25 minutes, covered. Then, remove the foil and bake for an additional 10 minutes until the cheese is bubbly and golden brown.
Once baked, let the dish rest for about 5 minutes. Garnish with chopped fresh herbs for a bright, fresh finishing touch.
Serve the shells warm, enjoying the tender pasta filled with creamy, flavorful spinach and topped with melted cheese. Dig in and savor each comforting bite!
