Preheat oven to 180°C. Brush a round 24cm (base measurement) cake
pan with melted butter to lightly grease.
Place sweet potato in a steamer over a saucepan of simmering water
(make sure base of steamer doesn't touch the water). Steam, covered, for
10 minutes or until tender. Set aside to cool.
Preheat a chargrill over high heat. Brush both sides of eggplant and
zucchini with the oil. Cook one-third of the eggplant and zucchini for 1-2
minutes each side or until golden. Transfer to a plate. Repeat, in 2 more
batches, with the remaining eggplant and zucchini.
Arrange eggplant over base of pan. Sprinkle with one-third of cheddar. Top
with sweet potato and sprinkle with half the remaining cheddar. Top with
zucchini and sprinkle with remaining cheddar.
Use a fork to whisk together the egg, cream and parsley in a bowl. Season
with salt and pepper. Pour egg mixture over vegetables and sprinkle
extra cheddar. Bake in oven for 35-40 minutes or until just set. Remove from oven. Set
aside in pan for 10 minutes to cool. Turn onto a plate and cut into wedges to serve.