Good beef heart recipe is just keeping things simple:
I use a 1:1 ratio of beef heart and krill, add a few garlic cloves if you like, though it's not necessary.
Get some high quality flake food such as Ocean Nutrition and if you want some color enhancement you can add TetraBits. Total ratio should be 5:5:1 so 5 parts beef heart, 5 parts krill and 1 part flake.
Throw it all in a blender and go to town, it stinks like hell. Then just ball it up into tennis ball sized nuggets, wrap in suran wrap and freeze it...
Simple as that =)