In a large sauté pan, warm 3 tablespoons of olive oil over medium heat, add the eggplants and garlic, and cook for 3 minutes.
Add the tomatoes and cook uncovered for 20 minutes or until the mixture is soft and can be crushed with a fork.
In a mortar, muddle the anchovy fillets until they become a paste and mix them with 2 tablespoons of olive oil.
Add the anchovy mixture to the vegetables.
Blend the flour with the milk and add it to the vegetables.
Season with pepper.
Mix well and put the mixture in an oiled gratin dish.
Sprinkle on the panko and the remaining olive oil.
In a preheated to 350°F oven, bake the gratin for 30 minutes.