I was staring at my steak earlier (as I often do) and I started to think about the fat around the edge and it struck me that it would almost certainly be largely saturated. I then got to thinking about the relative melting/boiling points of saturated vs unsaturated fats and it stuck me that grilling a steak would very likely result in a lot of the unsaturated fats running off.
I dug up a study that seems to agree with my gut feeling:
Couldn't tell you what the actual amounts were.
So, here we are patting ourselves on the back for eating grass-fed meats, perhaps shunning any sort of additional source of n-3 (or n-6 for that matter)fats, but what if, after cooking, we're left with mostly saturated fat? I don't think this fat is unhealthy per se, but I doubt that we would thrive to the same extent as it we were eating more monounsaturated, n-3 and n-6 fats in addition to it. Don't get me wrong, this isn't a defense of conventionally raised meats, because there's a lot more to it than simply unsaturated fat ratios/content. I personally wouldn't consider switching back. Additionally, I don't really advocate eating raw meat, though some swear by it. If someone can consistently source safe meat and eat it raw, they may have an advantage, at least inasmuch as fatty acids are concerned.
That all being said, I think one viable solution could simply be to eat a range of nuts. Macadamia and hazelnuts are skewed heavily toward monounsaturated fat, while walnuts are skewed toward n-6 (let's not forget that n-6 is an essential fatty acid, in spite of the extent to which it is maligned by the paleo community). You'll get some n-3 from the walnuts, but if you relied upon them solely for the polyunsaturates, you'd have a heavy skewing toward n-6. If you can eat them raw without ill-effects, then that is very likely optimal. I don't think the PUFAs would run off of roasted nuts to the same extent as meat, however.
As much as I hate to admit it, fish oil might be a good idea to get n-3s after all. I suspect that cooked fish has the same problem as cooked beef, so we may be leaving all of the salmon's n-3s in the bottom of the pan. I'm not sure if the advertised amounts of EPA/DHA on the sardine boxes are for raw or processed fish, or if the latter, if it still just runs off when we drain them. I don't how practical it would be to rely upon sushi for one's n-3, but if you did, you'd probably want to focus on wild salmon (sake) and mackerel (saba).
Marrow is also a dense source of monounsaturated fat, and I suspect that hominids had an extensive period where we ate little meat but a lot of marrow and brains (a dense source of 22:6 n-3) from carcasses that other predators killed. I eat a small amount of marrow with my steaks, and since it starts out 60-something% MUFA, I doubt there's much lost in cooking, as it appears to be the same volume afterward. I could see me pursuing a human-grade equivalent of those cow femur marrow bone rings that one might give their dog if I'd like to more MUFAs. Avocados are clearly a great source of MUFAs as well. As for brains, no thanks.