Butter the bread on both sides. Layer each piece of bread with the cheese slices.
Heat a large frying pan over a medium heat and add a teaspoon of olive oil in when hot. Put two slices of bread in the pan, cheese side up and top one slice with a handful of blanched asparagus spears.
Put a lid on the pan to allow the cheese to melt and the asparagus to heat through.
After a couple of minutes, remove the lid and sandwich the two halves together. Press down firmly with a spatula.
Repeat with the second sandwich. Serve with cress, pickles, or chutney.