Place the salmon fillet into a tray and completely cover with the marinade. Leave for 8 hours then rinse under cold water. Cut into 3” x 2” pieces, then pan fry in a little olive oil. Whisk together the 2 mustards and add the vinegar. Then slowly incorporate the olive oil, season, and add the chopped chives and lemon juice.
To serve, place the broad beans and morel mushrooms on a plate, place the salmon on top, then the poached egg on top of that, drizzle the mustard dressing over the top. Toss the salad leaves in the mustard dressing then serve to the side of the salmon.