Preheat the oven to 200 degrees. Place the wild salmon fillet on a cedar wood plank or in a roasting pan. Coarsely chop the fresh dill and distribute it together with the juice of half a lemon over the fish.
Slide the plank or roasting pan into the oven and roast the salmon for twelve to fifteen minutes until cooked. Meanwhile, heat the ghee in a frying pan over medium-high heat. Trim the tough ends of the green asparagus and sauté the vegetables in the pan for a few minutes until tender-crisp.
Remove the salmon from the oven. Divide the sautéed green asparagus among the plates and place the cooked salmon fillet on top or alongside. Sprinkle everything to taste with fleur de sel and some pepper and serve immediately.