Cream Of Asparagus Soup (cr?me D'asperges)

Cut the tips from 12 asparagus spears, 1? inches from the top and halve the tips lengthwise if thick, reserve for garnish. Cut the stalks and all the remaining asparagus into ? inch pieces, cook the onion and thyme in 2 tablespoons of the butter in a large heavy pan over a moderate to low heat, stirring, until the onions are softened about 2 minutes. Add the white wine, asparagus pieces, salt, and pepper to taste, bring to the boil, and cook until the liquid is reduced by half Add 5 cups of the chicken stock bring to the boil; reduce the heat and simmer, until the asparagus is tender, about 8 to 10 minutes. While the soup simmers, cook the reserved asparagus tips in boiling salted water until just tender, 3 to 4 minutes, then drain. Pur?e the soup in batches in a blender until smooth, transferring to a bowl (use caution when blending hot liquids), and return to the pan. Stir in the double cream or cr?me fra?che , and then add more stock to thin the soup to the desired consistency. Season with salt and pepper, bring the soup to a boil, and whisk in the remaining tablespoon of butter. Add the lemon juice and garnish with the asparagus tips. Serve and Enjoy