Quiche with salmon, leek and echalion

For 4 people, chop 2 echalions and fry it with butter. When golden, add 4 middle size sliced leeks.
Fry it for 5 min then cover and let simmer for 10 min.
Cut into pieces 300 g of raw salmon and 150 g of fresh goat cheese. Add it to the pan and let it cook for 5 min. Then add 40 cl of liquid cream, 70 g of grated Gruyère, 1 teaspoon of strong mustard.
Put salt, pepper and mix it. Let it reduce for 10 min.
Put a roll of flaky pastry in a tart dish and cover it slightly with mustard.
Take out the pan from the burner and add 4 eggs beaten in omelette.
Put the preparation on the pastry, and put it in the oven at 210°C for 25 to 30 min.