Caramelized Onion and Mushroom Cake with Egg filling

I made this cake for our vegetarian friend who come over last week. This time I had to create something without fish so I have chosen some great ingredients instead: onion, mushroom and egg.

Caramelized Onion and Mushroom Cake with Egg Filling

Ingredients for the cake

350 g plain flour
1 1/4 tbsp baking powder
8 tbsp sunflower oil or 100 g butter, melted and cooled
pinch of salt
freshly ground black pepper
3 eggs
300 ml butter milk 
3 onions finely chopped
1tbsp red wine vinegar
2 tsp sugar
150g tinned mushroom chopped or fresh mushrooms fried slightly on a knob of butter

Ingredients for the filling
7 hard boiled eggs
4 tbsp mayonnaise
3 tbsp soured cream (only 1-2 if you want to pipe the cream)
1 onion finely chopped
2 garlic bulbs
1-2 tsp english mustard
freshly ground pepper

cucumber to decorate

First prepare the filling so the mixture can intensify the taste with time. Peel the eggs and chop it to small pieces, you can use a food processor if you want. Add the mayonnaise, soured cream, finely chopped onion and garlic, mustard and season with pepper if needed.
Just mix together, cover with cling film and place it in the fridge for at least 2 hours.

Heat 2 tablespoons of the oil in a frying pan. Add the onions and cook for  3 minutes, or until beginning to soften. Add the vinegar and sugar and cook, stirring occasionally, for a further 10 minutes or until golden brown. Remove from the heat and leave to cool.

Meanwhile preheat the oven to 200C and spray the tin with a vegetable oil based separating agent.Sift together the flour, baking powder, salt and pepper to taste into a large bowl.

Place the eggs in a large bowl and beat lightly, then beat in the buttermilk and oil. Make a well in the centre of the dry ingredients, pour in the beaten liquid ingredients and add the onion mixture and the mushrooms. Stir gently until just combined: don't over-mix  Spoon the mixture into the tin and spread evenly to be layered.

Bake in the prepared oven for 20 minutes, or until well risen, golden brown and firm to the touch. Leave to cool in the tin for 5 minutes then turn it upside down and remove the silicone cover  and the steel ring

.

 When it is cooled, all you have to do is to spoon the filling into the cavities, decorate and serve:)

In the end I served with some balsamic glaze and mixed salad with olive oil on top....The photo of the sliced cake not the best again.........hmm I have to learn how to use other function on the camera than the automate.