First prepare the asparagus, wash and remove, break off the hard bottoms. If you are going to pre-bake them in the oven, arrange them on a baking sheet with baking paper and drizzle with oil, salt and bake at 220 degrees Celsius for about 15 minutes to brown them a bit.
Chop the onion and sear it on olive oil until lightly browned. Add chopped garlic, cook for a minute to simmer, then add other ingredients: asparagus (if added fresh, cut them into smaller pieces first), butter beans, washed spinach leaves. Season with salt and pepper and pour in 6 dl of liquid (soup or water) and cook for 15 minutes or until the asparagus are softened.
Then blend the ingredients into a smooth soup. Stir in the lemon juice and taste, add seasoning if necessary. Serve hot with sour cream, chopped chives and crispy bacon.