Pre-heat a fan assisted oven to 160°C.
Cover the potatoes in olive oil, add the garlic and thyme. Cook slowly until soft (in the kitchen we call this confit, it’s a French term for this method of cooking).
Once cooked, allow the potatoes to cool in the oil at room temperature.
Drain the potatoes from the oil and break up into rough large chunks using a fork. You can keep this oil to use for another day.
Mix the eggs, yoghurt and turmeric in a bowl.
Over a gentle heat in a large frying pan with a little olive oil, sweat the diced onion until softened without browning.
Break the nori and kombu sheets up roughly with your hands and, in a frying pan, add to the above yoghurt mixture along with the potatoes.
Allow the egg mixture to set on the bottom of the pan but keep the heat on a low temperature to ensure it doesn’t overcook.
Sprinkle the onion seeds, chives and grated Davidstow® 3 Year Special Reserve Vintage cheddar over the top of the mixture. Now place into the pre-heated oven and bake for 8 minutes. Then turn the oven up to 180°C for a further 4 minutes or until golden brown. Remove from the oven and cool at room temperature. Once cool, carefully remove the frittata onto a chopping board. Cut into equal sized portions and serve.