This is a recipe for white sauce, suitable for use in lasagne.
1 cup plain flour
1 cup oil
2 pints milk
a pinch of salt
Put the oil and flour into a pan and stir until there are no lumps left in the flour. Add a little milk and stir until mixed, then add a little more and stir. Continue until all the milk is added. Cook on a medium heat until the sauce thickens.