There are plenty of recipes that can be altered to suit the needs of every fish, Camshaft.
I already feed my goldfish Hikari Lionhead, bloodworms, boiled egg whites, etc so the gel foods focus more on high fiber but still cater to the fatty acids required.
Here's the recipe I use.
Ingredients
3-6 4 oz jars of baby food (any brand and flavor as long as appropriate; I use Gerber)
2-3 calcium pills (optional; I use Caltrate)
1-2 tablespoons of fish food (optional; I use Hikari Lionhead)
2-3 sachets of unflavored gelatin (Knox is best as Alga has sucrose added responsible for clouding the water badly.)
1 can of sardines/mackerel/tuna (90 grams I believe)
1 acidophilus tablet (optional; recommended for fancy goldfish who may have buoyancy issues)
1 multivitamins
Equipments
Microwave oven
Mortar and pestle or blender
Microwave container or bowl
1 tablespoon
1 fork
Cookie pans
A roll of wax paper
Instructions
1. Pound tablets first and then mix with baby foods.
2. Wash the fish (sardines/mackerel/tuna) to remove the tomato sauce completely.
3. Mix no. 1 and no. 2 together.
4. Boil water in the pot. Pour the gelatin in there and keep stirring.
5. Pour no. 3 into a microwaveable container and set microwave at medium and keep it on for a minute or two.
6. While waiting, wrap the cookie pan with wax paper.
7. Open the oven and get the bowl out of it.
8. Pour the thick into the cookie pans and make sure you get 1/4 inch thick of mix. If the mix seems to settle separately, stir it again with a tablespoon or fork.
9. Once done, place the cookie pans inside your fridge.
Wait for a few hours until the gel food thickens. Make sure beforehand the mixture is thick, not too runny. If it is runny, you are adding too much water and very little gelatin powder, in this case add more gelatin, spread it around on the thick and stir. Pour a little boiling water or rather place it in a microwave oven again and wait for another minute.
Gel foods should be kept refrigerated at all times. If possible, make a recipe that should last in 3-4 weeks only. You can feed the rest to your furry pets.