1. Slice it into not too thick slices (about 1 cm).
Quick option: grill them for 5 minutes in the air fryer (180°C) or in a pan with a little oil and salt (so they are slightly golden).
2. In a pan or the Monsieur Cuisine (sauté mode), heat 1 tbsp of olive oil.
Add the minced onion (and garlic if you like), then the chicken cubes.
Let it brown for 5 to 7 minutes while seasoning (salt, pepper, herbs).
3. Pour the can of crushed tomatoes or passata over the chicken.
Let it simmer for an additional 5 minutes to thicken the sauce. Adjust salt, pepper, and herbs.
4. In a dish (or a large air fryer-compatible dish if you prefer this mode), arrange a layer of grilled eggplant slices.
Spread half of the chicken-tomato sauce mixture on top.
Add small pieces of fresh cheese (or light cream) here and there.
Repeat for a 2nd layer: eggplant + remaining chicken in sauce + fresh cheese.
Finally, sprinkle with grated cheese.
5. In the oven: Approximately 20-25 minutes at 180-190°C (even if it is slow, you have time to do something else).
In the air fryer: If the size of your dish allows it, 15 to 20 minutes at 180°C may be enough. Make sure the gratin doesn't burn.
6. This gratin is delicious as is (without accompaniment) thanks to the eggplant and chicken, which are already filling.
If you want an additional starch: cook some whole grain rice or whole wheat pasta while the gratin finishes browning.