Put the butter and oil in a pan and heat
When foaming add the asparagus tips and cook for 2 mins until softened
Remove and leave to one side
Add the shallots , asparagus and garlic and cook for about 10 minutes until softened
Add in the spinach , stir well
Add the stock and bring to the boil
Blitz with a hand blender
Season to taste
Serve with the reserved tips scattered on top
For a smoother soup add a little more water or pass it through a sieve