I do something similar. I do noodles rather than pasta, sometimes rice as well. I use sardines but will look in to mackerel as well now that you mention it. I grate fresh turmeric over the top as i grow it myself and usually add a heap of chillis.
I find that the pasta is less fuss and the most cost effective. The salmon roll is sold at our local tucker box for dogs , it has soft bones in like canned salmon and they love it. At $4 a roll it is even cheaper than the mackerel and a nice change . When I can get the 10kg bags of rice for half price I alternate the pasta for rice.
