I have much respect for the ocean and all fish. So you will see that try to use has much of the fish as possible.
For this recipe I will be using Bonito Tuna. Where I am from we have a lot of them. When I go fishing its very common to catch them, but most fisherman release them or use them as bait. Here's a great way to use the fish.

Step 1: Cut the Fish Into Chunks

Cut the fish into chunks and try to remove all the bones. Clean fish it's more fun for everyone.

Step 2: Boil for 15 Mins

Now boil some water with a bit of sea salt, throw the Tuna chunks inside and leave it for 15 mins.
Then take out and let it rest. If you see now you already have a resemblance to Canned Tuna just like the ones you find in the supermarket.

Step 3: Throw the Fish Remains Into the Pan

You can throw the remains of the fish and boil for another 5 mins. Throw the remains away. After, I use the tasty water to mix in with my dogs bowl of food. Trust me your dog will love it(its very healthy as well). Look at her face ?

Step 4: Use the Small Chunks to Do Patê

For the canned tuna we want the big chunks so for the small ones heres another recipe.
Throw all the small bits into the food processor with a decent amount of mayonnaise, herbs, olive oil, a pinch of salt and any other herbs and spices you fancy.
Note: Put in a container and put straight in the fridge . Only serve when cold with crackers or a slice of bread.

Step 5: Now Grab Some Recycled Jars

Now grab some recycled jars and throw in all spices and herbs you feel like. Or you can leave it plain simple.
Fill each jar with half olive oil then close it and give it a good old shake. Then start by adding a couple of tuna chunks, then close the lid and shake again. While you grab each chunk, squeeze it gently with your fingers so it opens the chunks for the spices and olive oil can go right into the Tuna for a great flavor.
I know its a lot of olive oil and its not cheap but you can still use that tasty olive oil on your salads or even to fry a beautiful fish fillet(works with any fish).

Step 6: And Voilà

Fill up the rest of the jar with olive oil and close the lid.
Now you have homemade canned Tuna. Add it to your salads, sandwiches, home made pizzas and any other dishes you might like.
Leave it in the fridge, after a couple of days the flavor will have been absorbed by your Tuna and you can enjoy. I would suggest you consume it in 6 months, still enough to enjoy it over the winter.
Note: Make sure all your Tuna is under olive oil.