Using a sharp kitchen knife, slice the asparagus spears diagonally into 2 mm thick slices. Also slice the smoked salmon very thinly. In a non-stick frying pan, cream the butter and add the asparagus spears with the sugar. Roast the asparagus until golden and al dente. Season with salt and a little sugar.
While the asparagus is still warm, place the salmon on top and drizzle with the oil and vinegar. Sprinkle with pumpkin seeds and serve on the spot.