Not sure what you can find in your country but we have tinned mackerel (with tomato typically) in Norway. I can highly recommend.

It's not thaaat fishy, I didn't grow up eating it. After having it a few times it really grew on me.

Super cheap and an easy way to get it into my diet. I have 2-3 tins per week. I eat it for breakfast mashed on bread (our bread is like a hard cracker), sometimes with a bit of mustard, or butter spread first.