Preparation

1. Wash the jars and lids. Leave to dry.
2. Trim the tuna to remove all bones and all dark spots in the flesh. Peel the carrot, quarter it lengthwise and cut into 1 inch pieces.
3. Cut the tuna into pieces that will fit into the jars. Fill the jars tightly, up to the level of the shoulder of the jar (this should leave a bit of head space). Add one piece of carrot to each jar. Add 1/4 teaspoon sea salt and 3 tablespoons olive oil to each jar.
4. Wipe the rims of the jars carefully. Screw the top on to hand tight.
5. It is important to follow the instructions that come with the pressure cooker, as each model is a bit different. Stack the jars in a pressure cooker. Add water to the cooker and close. Cook the jars at 15 psi for 90 minutes. Allow the cooker to cool before removing the jars.