To make the pastry, combine the flour and a pinch of salt in a bowl. Using your fingertips, rub in the 85g butter and lard until it resembles breadcrumbs. Add the water and mix. Turn out onto a floured board and knead briefly to form into a ball. Wrap in cling film, chill for 1 hour, then roll out and line a 18cm flan ring; set aside in the fridge.
Beat the egg and yolk in a bowl; add cheese, salt, pepper and cream.
Melt 15g butter in a pan; cook the bacon and onion until brown in colour, about 10 minutes. Stir bacon into egg mixture then pour into pastry case.
Bake in the preheated oven until the quiche is set and lightly golden, 25 to 30 minutes.
You can replace the lard or vegetable fat with more butter or margarine, if desired.