So. Here's how to make excellent chicken-pumpkin soup.
First off, make your own stock, it's seriously easy and tastes amazing. Did I mention seriously easy? If you have a slow-cooker it's even easier, but if you don't all you need is a big pot and your stovetop. Man, I wish I had a slow-cooker...
So. Go buy a chicken frame (what chicken carcasses are usually called in butchers / supermarkets). Here they're about $3 a kilo, and a kilo of chicken frames will make you lots and lots of stock. You can also just use a pile of raw chicken bones, but frames usually have a reasonable amount of meat left on them anyway, which makes good tasty stock.
Did I mention simple? All you've gotta do is stick the chicken in a big pot & cover it with water & simmer the hell out of it & whatever you want to use for extra flavour. I usually peel an onion & quite a lot of garlic and throw that in. it doesn't matter if they get all bits-y and mushy, 'cause later you'll strain the weird stuff out of it anyway. If you get scum floating on the stock as it cooks, you can scoop it off with a spoon, but straining later on will take care of this anyway, so I usually don't bother. I also use a bouquet garni for flavour. (Generally I'd suggest about 3L of water to a frame.)
Let it all simmer gently for a few hours (this is where a slow-cooker is awesome - you can put it all in, set it to low and head off to work or whatever.), then let it cool. Once it's cool, stick it in the fridge (I leave it in the pot for this, but decanting is fine if the pot won't fit) and chill it. This will make the fat coagulate on the surface, and you can skim it off (now you've got flavour without grease). Once you've removed the fat, strain the liquid through a sieve. You'll get a bunch of grit & stuff out of it - just throw that away. Pull any meat still on the bones off, and return it to the stock.
You can use stock like this for risotto, soups, stews... whatever you want, really. It'll keep for 5 days or so in the fridge, or you can freeze it for up to 3 months. When you're using it, you can dilute it a little more if you want - it really depends on what you want it for, and the original strength you made it at. Another tip - if you don't have much freezer space, simmer the liquid to reduce it down, and you can freeze it as icecubes.
Anyway, getting on to the soup part. I didn't have much stock left, so the soup base was 1/2 stock, 1/2 water.
1 butternut pumpkin
1 large sweet potato
several garlic cloves (I use about 6-8, to make 3L of soup)
seasoning to taste
carrots, or any other hard vegetables you feel like using - can be chopped or grated...
Steam the pumpkin and sweet potato with several peeled garlic cloves. When cooked, mash (put the steaming water in, too). Put the stock & water, onion, & mash on to cook; when it's bubbling, add the chicken pieces and chopped veggies. Add salt, pepper, and whatever herbs / spices float your boat until it tastes right, and when the chicken & veggies are cooked, you have a meal!
Should keep for several days in the fridge, and freezes well, although the texture of carrots can get a bit funky once they've been frozen.