Heat oven to 220C/200C fan/gas 7.
Put all the vegetables, except the chicory
and celery leaves, in a large, non-stick
roasting tin. Pour over 2 tbsp olive oil
and season. Mix everything and spread
into a single layer. Bake for around
45 mins, tossing once or twice, until
the vegetables are tender and beginning
to turn golden.
Meanwhile, make the pesto. Pop the
parsley, cashew nuts and garlic in a food
processor. Blitz until quite smooth. Stir in
the olive oil, lemon juice, Parmesan and
some seasoning. Adjust the thickness
with a little more olive oil, if you like.
Heat a griddle pan. Rub the steaks with
the remaining oil and season. Cook on
each side for around 4 mins for medium,
or to your liking, adjusting the time
depending on the thickness of the steaks.
Rest the steaks, covered, for 5 mins.
Toss the chicory and celery leaves
together with roasted roots. Serve
alongside the steaks and spoon a
generous dollop of pesto on top.