Cut off the tough ends of the asparagus. Pour water into a narrow tall saucepan, bring it to a boil, add lemon juice, sugar, salt and 1 tbsp. l. olive oil. Lower the asparagus stalks vertically into the pan so that their upper part, with the buds, is steamed above the water level. Cover with a lid, cook 5 min. Cut the cooked asparagus into slices from the bottom side. Put carrots, celery, zucchini in a small amount of water and also cut into small circles. Cut the puff pastry into 4 portions and bake in the oven at 160ºC until golden brown, about 5 minutes. Fry the prepared sea bass fillet in a pan, in olive oil, for 1.5 minutes. from each side; season with salt and pepper. Peel the onion, chop, fry in olive oil, pour in white wine, evaporate by half. Introduce cream; When the sauce starts to thicken, add the butter. Do not remove the pan from the heat for another 2 minutes, while thoroughly mixing everything with a whisk. Remove from fire, strain. Put the asparagus on a plate, pour sauce over it; then lay out pastries with vegetable circles and fish.