1: Cut 150 g smoked haddock into flakes. Set aside.
2: Prepare and cut 100 g mushrooms into strips and sprinkle with 1 tablespoon lemon juice. Reserve.
3: Cut 4 slices bread. It is not essential, but much better, to toast the bread before assembling the tartines. Then arrange the slices on a sheet of cooking parchment laid on a baking sheet. Preheat the oven to 390°F (200°C)
4: Spread a layer of leek fondue on each slice.
5: Then add some mushrooms.
6: And top with the haddock.
7: Put in the oven for 5 to 10 minutes.
8: Serve hot or warm.
Remarks
You can use another smoked fish instead of the haddock, if you prefer.