Peel the zest thinly from one orange. Squeeze all three oranges. Measure 250 ml of juice. Combine the juice with the white wine and orange zest, then reduce over medium-high heat for 15-20 minutes until reduced by about half.
Peel the asparagus. Cook in salted water over medium-high heat for 8-12 minutes until tender-crisp, depending on thickness.
Finely dice the shallots. Heat the butter over medium heat, add the shallots, and cook for 2 minutes until softened. Dust with flour and cook for 1 minute, stirring. Strain the reduced orange mixture to remove the zest. Pour in the cold cream first, then slowly add the strained orange stock, stirring to prevent lumps. Bring to a boil over medium-high heat, then reduce to medium-low and simmer for 10 minutes. Season to taste with salt, pepper, and tarragon. For a smoother sauce, strain through a fine sieve.
Heat the clarified butter in a skillet over medium-high heat. Fry the salmon steaks for 4-5 minutes per side until the internal temperature reaches 63°C (145°F). Season with salt and pepper. Serve with asparagus and orange sauce.