Threre are a ton of recipes out there. Most involve using a blender to puree different mixtures of shrimp, fish, vitamins, veggies......... held together with geletin as a binder. Never tried them personally (seems like a lot of work). I think it's easier to just feed a good pellet/flake food, and a variety of frozen (bloodworms, mysis shrimp, white mosquito larva, cyclops-ezz, baby brine shrimp........). Pick two or three (I use bloodworms and mysis primarily) and rotate through them.
Marine One makes a frozen food similar to hobbiest formulas. I feed this occationally, but it needs to be chopped up, and fed very sparingly so that you don't foul the water.