Heat the oven to 180 degrees Celsius.
Slice the tomatoes in half and place them on a baking tray. Lightly brush with olive oil and place in the oven to roast for 20 minutes.
Heat the olive oil in a pan and sauté the vegetables gently for 7 - 10 minutes until soft.
Separate the eggs into 2 separate bowls and beat the egg whites until they form stiff peaks. Beat the egg yolks together with the ricotta, mustard, flour and seasoning. Add the leek and onion and stir through. Fold the egg yolk mixture through the egg whites. Heat some oil in a non stick pan and add the leek and egg mixture. Gently cook easing the pancake from the sides until it's almost cooked through. Cook the top of the pancake by placing the pan under the grill until it's lightly golden on top.
Serve with steamed English spinach and roast roma tomatoes.
Note: A study in China on the effects of eating vegetables from the allium family, which include leek and onion, discovered that men with high allium consumption had a statistically significant reduced risk of prostate cancer than those with a low consumption.
Makes 4 servings