Method:

Preheat the oven to 200°C and prepare a tart tin.
Combine the flour, butter and salt until the mixture resembles bread crumbs using your finger or a food processor. Add the egg and water until a dough formed. Cling wrap the dough and rest for 15 minutes. In the meantime, in a pan drizzle oil and add the onions, sugar, balsamic vinegar and thyme. Cook on a medium to low heat until caramelized for about 15 minutes, season with salt and pepper to taste, remove from the pan and cool the filling. In a saucepan, add the butter and melt on a medium heat. Add the flour and nutmeg and cook for 2 minutes. Whisk in the good hope soy and cook the sauce until thickened. Remove from the heat and add the Emmental cheese, mix through and season with salt and pepper to taste. Roll the pastry out and place in the prepared tart tin, blind bake for 15 minutes. Remove from the oven, add the onion filling and spread evenly in the tart. Pour over the cheese sauce and spread. Crumble on the feta and return to the oven to brown the top. Once out the oven top with dressed fresh greens and enjoy!