First make the ragu or meat sauce.
Heat the oil in a frying pan, then cook the
beef in two batches for about 10 mins
until browned all over. Finely chop 4
slices of prosciutto, then stir through the
Pour over the tomato sauce and stock,
add the nutmeg, then season. Bring up
to the boil, then simmer for 30 mins
until the ragu looks rich and is well
coated in sauce. Can be left for 3 days
in the fridge or frozen for 3 months
(although not if the tomato sauce has
previously been frozen).
Heat oven to 180C/fan 160C/gas 4. To
assemble lasagne, lightly oil an ovenproof
serving dish (30 x 20cm). Spoon over
a third of the ragu sauce, then cover
with lasagne sheets. Drizzle over about
one quarter of the white sauce. Repeat
until you have 3 layers of pasta. Cover
with the remaining half quantity of white
sauce, making sure you can’t see any
pasta poking through.
Tear the mozzarella into thin strips,
then scatter over the top. Arrange the
rest of the prosciutto on top. Bake for 45
mins until the top is bubbling and lightly
browned. (The uncooked lasagne can be frozen. If baking from frozen, add another 45 mins to the cooking time).