Yes! But unlike alcune, qualche is followed by the singular. You can think of the use of everybody in English. It refers to more than one, but it is followed by third person singular conjugations.
- Mangio qualche biscotto - I eat a few cookies
- Leggo qualche libro - I read some books
It's certainly not slang or dialect: if one were describing how to make a dish, one might very easily (and correctly) say, "I fry some onion in a skillet, add some garlic...," and so on. There are definitely circumstances in which "We roast some sweet potato" would be just as acceptable.
You mean "noun", yes?
Anyway, there is a similar usage in some English vernaculars which most often are found in rural areas with roots back several centuries. I don't know whether it's a link to a long-ago past usage or just bad grammar, but phrases like, "We're going to cook us up some potato" would not be seen as odd.
Or how about, "We're going to get some beer." What people mean by that is that they are "going to get some beers"
Or "We're going hunting and we're going to get some pheasant."
I think that it is just poor grammar to say "cook us up some potato"! We don't say "cook up" unless it is a scheme or plan and then it is used somewhat ironically. On the other hand, you definitely can say, "I am going to get some beer." You could also say I am going to get some milk, some apples, etc.