Carefully wash the potatoes and the chayotes. Peel them and then cook in a large saucepan of water. Mash with a fork.
Peel the onion and chop finely. In a saucepan, sweat the onion and add the thyme and garlic and ginger mixture. When the onions become translucent, reduce the heat and add the potato and chayote mash and the egg yolk. Blend vigorously.
Dissolve the flour in the milk and pour onto the mash.
Then add 3 tablespoons of cheddar and melt.
Pour this mixture into an oven dish and sprinkle the cheddar and breadcrumbs on top. Brown for 5 minutes in the oven at 180°C.
