Peel the asparagus and place in the steamer basket.
Thinly slice the orange and lemon and place on top of the asparagus with the tarragon. Season with salt, pepper and a little sugar. Scrape out the vanilla stick and also place the scraped pod on the asparagus. Put the orange juice and poultry stock in the bottom of the steamer and mix with the scraped out vanilla pulp. Heat the orange stock to approx. 80 ° C and then cook the asparagus for approx. 15 minutes.
Then let the orange stock boil down a little and bind a little with the mixed cornstarch. Gradually stir in the cold butter and season with salt and pepper.
Lift the asparagus stalks out of the cooking basket and serve with the orange-vanilla butter. This goes very well with briefly fried chicken breast or turkey schnitzel.