Left a comment on Dave Walker's blog about parsnip gratin and then realised I'd never posted it here. (Thanks to Dave for now providing free parsnip cartoons.)
Peel and slice the parsnips and place in a buttered casserole. Cover with breadcrumbs, chopped flat-leaf parsley, and grated gruyere cheese. Tip over a small tub of single cream and a bit of milk.
Bake in medium oven. 45 mins for thin sliced parsnips. Longer for thicker.
Cover at last moment with more grated gruyere and some black pepper and either finish under a hot grill or with a blowtorch.
As ever if you can't work out the amounts to use or what a medium oven is or how thin is thin you shouldn't be attempting anything this complex. Buy some veggie burgers and have them with low salt baked beans.