Flourless lemon cake with rhubarb compote

3 eggs, separated

120g of granulated sugar

1/2 tsp bicarbonate of soda

90g of polenta, or fine cornmeal

90g of ground almonds

1 pinch of salt

3 tbsp of sugar

80ml of vegetable oil

2 lemons, juice and zest

200g of rhubarb

4 tbsp of water