I'm a bit confused about those saying that a roast dinner 'takes all morning' and that there are loads of pots to wash. This is how I do it:
Calculate cooking time for meat and out it in oven at correct temperature.
Peel potatoes (and parsnips if having) and put them in a pan of cold water.
Make batter for Yorkies, and leave it to stand.
15 mins before the meat is cooked, turn on heat under the spuds, and bring to the boil. Simmer for 10 mins, then drain.
Take meat out of oven, and put it somewhere warm to rest. Put extra oil in meat dish (Pan 1), put it in oven at Gas Mk 7 for oil to heat up.
Shake par-boiled potatoes in the pan so the edges go rough, then add them to hot oil in oven. Wash spud pan (Pan 2).
Peel and slice carrots and put them in Pan 2, covered in water.
After about 25 mins, turn potatoes in oil, add a little oil to each section of a Yorkshire tin (pan 3), put it in oven to heat.
Give Yorkshire batter a final whisk, then pour it into the pre-heated tin in the oven.
After 20 mins, check Yorkshires for rising, adjust oven if necessary. Turn on heat under carrots, and allow to come to the boil. Boil for 5 mins, then add any other veg (sprouts, green beans) to Pan 2 and bring back to the boil.
Slice the meat and return it to a warm place.
Take roast potatoes (and parsnips) out of oven and put on to plates, drain off excess fat and make gravy in the pan.
Take puddings out of oven and add to plates, along with sliced meat. Drain veg, put on plates. Add gravy.
That's 3 pans (plus a Pyrex jug I use for making Yorkshire batter), and a lot of time waiting for things to cook, rather than working in the kitchen. Yes, the meat rests for around 45 mins, but it doesn't get cold, and turns out more tender that way. We don't have mash with roasts, but if we did, that would only be one more pan!