Preheat the oven Gas Mark 3, 170°C.
Lightly butter large 4 ramekins.
Divide the mushrooms and ham between the 4 ramekins, reserving some mushrooms for garnish. Pour a little tomato juice into each one. Carefully break two eggs into each dish, sprinkle with cheese and seasoning.
Place the dishes on a shallow roasting dish, pour boiling water around them to cover half way up the ramekins. Place ramekins in the oven. Check the baked eggs after 10 mins. The egg white should be just set with the yolk still runny but if you prefer your egg a little more cooked, bake for another 2-3 minutes. Garnish with mushrooms and serve with fingers of hot toast for dipping into the yolks.