Heat the oven to 350 F (175 C). Lightly oil a 9 x 13-inch baking dish.

Brown the beef in a large skillet, breaking it into crumbles. Drain excess fat and transfer the beef to a bowl.

Add the tablespoon of oil to the skillet. Soften the onions and peppers for 5-7 minutes. Return the beef, then stir in the tomatoes and their juice, paprika, garlic powder, half the herbs, and half the salt and pepper. Simmer briefly to combine; keep the mixture moist.

Arrange overlapping potato rounds across the baking dish. Season with the remaining salt and pepper. Spread the beef mixture evenly over them.

Seal tightly with foil. Bake for about 2 hours, checking near the end: a knife should pass easily through the potato layers. If still firm, cover again and continue baking until tender.

Remove the foil. Mix both cheeses and scatter evenly over the ENTIRE surface, including every edge, so no potatoes or beef remain exposed. Sprinkle with the remaining herbs.

Bake uncovered for another 15-20 minutes, until the cheese has melted into a continuous topping and developed golden patches.

Rest for 10 minutes. Cut a small portion, slide a broad serving spatula underneath the potato layer, and transfer gently onto a separate plate.