Make pastry by sifting flour and rubbing in the first measure of butter.
Add the water and knead until smooth. Roll out and line an 8" flan dish. Prick base and bake at 200 degrees C for 15 minutes.
Make filling by melting the second measure of butter and the oil and frying the onion and garlic for about 10 minutes until soft but not browned. Add the mushrooms and cook for a further 3 - 4 minutes. Stir in the chick peas, parsley, salt and pepper.
Put into hot flan case.
Beat together the egg and milk and pour into flan case.
Scatter cheese over the top and bake 40 - 50 minutes until set and golden brown.