Potatoes, sweet potatoes, butternut squash, sweet peppers, celery,sweetcorn on the cob, tomatoes, green beans, parsnips, carrots, onions and courgettes..and anything else you like to experiment with along the way..all roast really well with herbs and a little oil and garlic.
You should chop everything up with the vegetables that need longest being cut into the smallest pieces or else you can par-boil them for seven or eight minutes..carrots and potatoes, or three minutes for parsnips which are then easy to core..place everything into a bowl and add three or four cloves of finely chopped garlic and a teaspoon of dried herbs.If you want to use fresh herbs then a couple of tablespoons of mixed, finely chopped basil, rosemary, oregano, marjoram etc..and a couple of tablespoons of olive or sunflower oil, stir everything gently to coat and then arrange in a roasting dish and cook for 40 minutes at 170 and check..the exact time will depend on your oven, the vegetables used and the size of the pieces but this is a good enough starting point and should not actually burn anything.
Another method is to use a couple of teaspoons of green pesto instead of herbs with the olive oil..delicious by the way. and if you like garlic then add more and leave the cloves whole, they sweeten in cooking and will not over-flavour everything else if they are left whole; I usually add at least one bulbs worth of cloves and sometimes more.
Sprinkle with black pepper before cooking and add a small pinch, a quarter teaspoon, of chili powder if you want to give things just a little bit of a kick.
For a simpler dish, take half a dozen..or however many you want, good sized tomatoes and cut in half, push slivers of garlic into the open side of each half and arrange in a baking dish, drizzle with herbs, black pepper and olive oil or pesto and olive oil and bake for an hour at 160; add some sweet peppers about half way through cooking if you like them.
Make a package with baking foil, arrange green beans,onion, garlic and celery, a splash of oil and any herbs you like. Seal the package and bake in the oven for forty minutes at 170c.
These are really dishes of personal taste and After you have made them a couple of times you will find that you are making your own up as you go along preferring different herbs or spices and different mixtures of veggies..they all taste fantastic with roast lamb or chicken by the way, or on their own of course. The roast tomatoes and garlic make the best roast beef sandwiches or can be used to make a soup if you have any left, you peel off the skins..which is easy, place everything else in the blender and whizz until you have a puree, then add a pinch of salt and half a pint of milk..more if you have enough veggies, skimmed milk is fine and keeps it healthy..then warm up in a saucepan.
Garlic can be cooked on its own, you can actually buy a special little pot for roasting it in, or simply pile the cloves into a ramekin, oil and herbs as usual and cover with foil then bake for half an hour and test for tenderness..give it a little longer if you prefer. This is great served with meat or you can simply mash it up and add it to mashed potatoes or spread it on hot toast with just a little salt.