so mentaiko pasta... mentaiko is seasoned pollock roe (mentai = pollock, ko = babies... or something like that). it can be purchased frozen at asian supermarkets that cater to japanese or koreans expats. it's not unreasonably expensive - the package I bought cost $8 for what amounts to four servings (ie one box of pasta). it's not cheap like ragu, but perhaps it's a little better? what you get when you buy it is seasoned roe enveloped by the the natural membrane that it comes in. what's more pollock isn't a terrible fish to eat according to the monterey bay acquarium watchlist.
anyway, the video shows you how to prepare it, so i won't go into too many details, but i did change the recipe slightly. from what I gathered looking through various recipes online, what you are looking for is a creamy mixture of roe and fat. you can add in sake, soy, mirin and various other japanese seasonings in small quantities and the lipids are typically butter, oil, cream, or mayonnaise. like anything else, just adjust to taste. i made mine with unsalted butter (surprise!), a touch of soy and mirin, some sliced scallion, and I topped it with roasted salted seaweed.
the result was much much much tastier than the pre-packaged stuff, and it was quick and easy to make. in the picture above it doesn't look like there's much sauce, but trust me, one sack of roe is plenty for 4oz of pasta (1 serving). since the roe is frozen and defrosts very quickly this might just become a standby in my kitchen. you can also use mentaiko for onigiri (stuffed rice balls). perhaps that post will be coming soon, so stay tuned and go buy some mentaiko!