The herring, it turns out, was canned in a sweet sauce with hints of clove and dill.
I first melted butter and olive oil, and then added garlic and chanterelles. The mushrooms, it turns out, could have used a good cleaning — I have been spoiled by the spic-and-span white button mushrooms from the same supermarket, wrapped in the same plastic. I added a splash of white wine and steamed everything covered for a few minutes, while searching for a can opener. Then I added the herring, chopped into pieces, and some salt, and waited for the farfale to finish boiling.
I drained the farfale, mixed it into the sauce to coat in the butter-and-olive oil, and served with grated cheese. The dish, it turns out, was excellent.