I find it reasonably easy.

My way of doing roast (of any kind)
preheat oven 180 deg C, then cook covered with foil/lid of roasting dish 1/2hr for every 500g (round to nearest 500g) and an extra 1/2 hr. (eg 800g roast = 2x 1/2hr + 1/2hr = 1.5 hrs cooking time but check maybe after 1 hr if liking it pinker)

Then check meat with either meat fork (big long-pronged fork lol) or make a small cut in meat with knife and see if any/much red liquid comes out - if it does I tend to put in for about another 10min then re-check (I prefer my meat med-well done - ie not much pink).

If cooked take out of oven and leave for 5-10min to rest then cut it up (resting apparently lets the meat relax to make the cutting easier)

(you could check meat before the extra 1/2hr at the end if you like a pinker meat - I tend to do this if it's a chook more than any other roast)