Sweet potato, chicken breast and mushroom gratin

Turn the oven on to 200 °C, convection if you have it. Lightly butter the baking dish with some of the 10 g of butter.

Peel the sweet potato and cut it into 5 mm rounds. Slice the onion, clean the mushrooms and slice them. Cut the chicken breasts into 2 cm pieces.

Drop the rounds into a saucepan of salted boiling water, fully covered, and cook 5 min. Drain them well in the colander.

Melt the rest of the butter in the skillet over medium-high heat. Sear the chicken pieces for 5 min, stirring, season with salt and pepper, then set them aside on a plate.

In the same skillet, sauté the onion for 3 min, then add the mushrooms and cook 5 more min until their liquid cooks off. Put the chicken back in the skillet.

Off the heat, add the 8 cl of crème fraîche and the 5 cl of milk to the skillet. Stir, add pepper, and taste before adding more salt.

Spread half of the sweet potato rounds in the dish, pour in all of the chicken mixture, then cover with the rest of the rounds. Sprinkle with the 50 g of shredded cheese.

Bake 15 to 18 min at 200 °C, until the top is golden and the chicken is cooked through, with no pink and clear juices. Let it rest 3 min before serving.