Chanterelle And Gruyere Tart

Name: Chanterelle And Gruyere Tart
Ingredients: 1 1/4 cup all-purpose flour; 1/2 tsp salt; 8 tbsp unsalted butter (one stick), very cold and cut into 1/4 inch square chunks; 3-6 tbsp ice water; 3 tbsp butter; 2 x leeks, cleaned and thinly sliced; 1/2 x yellow onion, diced; 1 lb chanterelles mushrooms (cleaned and dried), pulled apart at vertical seams or sliced into 1/2 inch pieces; 1 tsp fresh thyme leaves; 1-2 tbsp madeira, sherry or dry port; 1 tsp salt; pepper to taste; 1 cup gruyere cheese, grated; 1/2 cup parmesan cheese, grated; 2 tbsp whipping cream