This meat sauce is the perfect example of Bolognese ... It is important to chop the vegetables finely, so that they are the size of grains of rice. Heat the butter and oil in a heavy-based saucepan.
Line an ovenproof rectangular dish of about 22 x 26cm/8½ x 10½in with a little of the ragù sauce, arrange sheets of lasagne over followed by ragù sauce, dots of mozzarella and white sauce and ...