I tend to roast game with a hot start at 220 degrees (fan oven so shelf doesn't matter) for 15-20 minutes, which gets the meat really hot and browns the outside. I should mention that I season it beforehand with salt, black pepper, some rosemary or mixed herbs, and a sprinkle of mace; sometimes I'll even smear it with a mixture of English mustard and garlic first.
Then I pour 1/4 bottle of wine into the roasting tray, cover it up with foil, sealing it as tight as possible, drop the heat to 160 degrees and leave it for at least another 45 minutes and even as much as 90 minutes, but which point it is really falling off the bone, moist and tender as can be.
The wine and juices are added to some stock and reduced to make the gravy while the meat is covered again with the foil and set aside to rest.
It's not a method for lovers of pink meat, but it's reliably succulent and very forgiving as regards cooking time in the second phase.
I'm sure you could do the veg in the same tin, but I prefer to do mine separately for more contrast in the flavours. Particularly good are parsnips, which I put in a roasting dish, season with salt, pepper and grated nutmeg, toss in a little olive oil, and sprinkle with dark cane sugar. These are then put in the oven and cooked in parallel with meat. After the first stage, they're given a good splash of balsamic vinegar, then covered up with foil and left to continue cooking until the meat is ready.
Freshly steamed broccoli, beans or other greens complete the dish - they go on 5-10 minutes before the meat and parsnips come out. All together it makes for an easy, reliable, and very tasty treat.