1. Prepare 4 leeks, finely slice them and set aside.
2. Prepare and finely chop 1 shallot, then set aside.
3. Cut 400 g of fish into small pieces, season them on the cutting board and mix.
4. In a large saucepan over medium heat, pour 5 tablespoons of olive oil and when it is hot, add the shallot, salt, and pepper. Cook for 1 minute without browning.
5. Add the sliced leeks, mix well...
6. ...and cook until they are just tender. Season with salt and check the seasoning.
7. Add the fish and mix.
8. Cook everything until the fish becomes opaque, a sign that it is cooked.
9. Add 250 g of cancoillotte, mix, and let it thicken according to your taste.
10. Enjoy without waiting too long.
11. I recommend using preferably a seasonal white fish, but you can adapt this recipe with whatever you find at your fishmonger's.