Heat oven to 200C/180C fan/gas 6.
Put the potatoes, asparagus, garlic
cloves, oil and lots of seasoning in a
large roasting dish (about 30 x 20cm).
Squeeze over all the juice from the
lemon halves, then cut them into chunks
and add them to the dish. Toss
everything together, cover the dish with
foil, and roast for about 15 mins.
Remove the foil and mix through the
rosemary. Season the chicken thighs
and arrange evenly in the dish.
Roast for another 25-30 mins until
the potatoes are tender, and the chicken
is crisp and cooked through. Serve
the dish in the middle of the table for
everyone to share.