Slice the leek finely across and check carefully for any remaining grit. Slice the asparagus on the angle finely, keeping the tips intact.
Heat a small pan of boiling water and blanch the tips briefly for 20 seconds. Remove with a slotted spoon and set aside to cool. Warm the stock to a simmer.
Heat half the butter and all the olive oil in a heavy based pan until just sizzling. Add the onion and bay leaves and stir over a medium heat until the onion becomes opaque but not coloured.
Add the spelt or rice and stir well so that each grain is coated with the oil. Season with salt and pepper. When the grains start to stick to the base of the pan add the prosecco or wine which will be absorbed quickly.
Start adding the hot stock, a cupful at a time. Once you have added half the stock stir in the leek and sliced asparagus, making sure they are mixed in well. Keep adding the stock little by little until the spelt is al dente- about 15 minutes. If you are using rice it may need a bit more liquid than the spelt.
Continue to cook over a medium heat, adding the remaining stock, until the risotto has reached a creamy consistency and the spelt retains a slight bite.
Stir in the crumbled goats cheese, the remaining butter, the reserved asparagus tips and the chopped chervil. Cover and sit for 2-3 minutes then serve scatters with chervil sprigs if you have some left.