Break or cut the cauliflower into florets.
Slice the fennel in half down the centre and cut out the V shaped root on both halves. Slice the fennel.
Place the cauliflower, fennel, and milk into a saucepan. Season with the salt and pepper. Bring to the boil and simmer until the cauliflower is just tender. Strain the mixture to separate the vegetables from the warm milk. Allow the milk to cool.
Bring a saucepan of water to the boil. Add some sea salt. Cook the peas for 2 minutes and add the whole silverbeet leaves for one further minute. Strain. Squeeze out any moisture in the silverbeet leaves.
Preheat oven to 180oC.
Heat the oil in a frying pan and fry the onions over a medium to low heat for 5-8 minutes or until softened and aromatic. Add the garlic and chilli and fry a further 30 seconds without browning. Toss in the cauliflower and fennel mixture as well as the peas (but not the silverbeet) and stir to combine. Remove from the heat and set aside.
Place the eggs and herbs and half of each of the parmesan and moxxarella into the milk and whisk well to incorporate more air than a traditional savory omelette. This will to allow the deep filling to have fluffier result. Line a 30 x 20 deep baking dish with baking paper. Spray with a little olive oil.
Place the cauliflower, fennel, pea and onion mixture into the dish. Lay the silverbeet leaves over the top. Pour over egg and milk mixture. Sprinkle the remaining cheese over the top and bake for about 45 minutes or until a little golden and just set but still slightly wobbly in the middle.