Batata Gratinada (Gratinated Potatoes) with Rich Tomato Sauce and Cheese

1.Preheat your oven to 190°C (375°F). Lightly grease a medium baking dish (approximately 20x25 cm).

2.Prepare the potatoes: Slice the peeled potatoes very thinly (about 2-3 mm thick) using a mandoline or a sharp knife. Place the slices in a bowl, toss with 1 tablespoon of olive oil, salt, and pepper.

3.Prepare the tomato sauce: Heat 1 tablespoon of olive oil in a small saucepan over medium heat. Add the chopped onion and sauté until softened and translucent, about 5 minutes. Add the minced garlic and cook for 1 minute until fragrant.

4.Stir in the crushed tomatoes, oregano, basil, and red pepper flakes (if using). Season with salt and pepper. Bring to a simmer, then reduce heat to low and cook for 10 minutes, allowing the flavors to meld.

5.Prepare the egg mixture: In a separate bowl, whisk together the 2 eggs and heavy cream (or milk) until fully combined. Season lightly with salt and pepper.

6.Assemble the gratin: Spread a thin layer of the tomato sauce on the bottom of the prepared baking dish. Arrange one-third of the sliced potatoes evenly over the sauce.

7.Pour half of the egg mixture evenly over the potatoes, followed by half of the remaining tomato sauce. Sprinkle with half of the mozzarella cheese.

8.Repeat the layering: Add the second third of the potatoes, the rest of the egg mixture, the rest of the tomato sauce, and the remaining mozzarella cheese.

9.Top with the final layer of potatoes. Pour any remaining sauce/egg mixture over the top layer, ensuring it seeps down slightly. Sprinkle evenly with the grated Parmesan cheese.

10.Bake for 45 to 55 minutes, or until the potatoes are tender when pierced with a fork and the top is golden brown and bubbly. If the top browns too quickly, loosely cover with foil for the last 15 minutes.

11.Remove from the oven and let the Batata Gratinada rest for 10 minutes before slicing and serving.