By Prue Leith
This is a good quick recipe for a vegetarian lunch. I make it with any fresh green veg – little florets of broccoli and cauliflower with a scattering of caraway seeds work well. Or you can vary the crumble by adding nuts to it or swapping the Cheddar for a blue cheese.
To make the crumble, rub the butter into the flour until the mixture resembles coarse breadcrumbs. Add half the tarragon (reserving the rest for the filling), th