Ask an adult to slice the ciabatta
loaf in half lengthways and heat
the oven to 200C/180C fan/gas 6.
Put the ciabatta loaf halves,
crust-side down, on a large
baking tray and drizzle with
a little olive oil. Pop them in the
oven for a few mins until just golden
and lightly toasted.
Put the olive oil, balsamic
vinegar, garlic and mustard in a
bowl, then whisk them together
with a fork.
Remove the toasted ciabatta
halves from the tray and drizzle
the bottom slice with about half
of the dressing.
Arrange the rest of the
ingredients in layers. Start with
a large handful of baby spinach,
then a few artichoke hearts.
Next add the slices of pepper,
the prosciutto, basil, mozzarella
and, finally, the red onion.
Drizzle over the rest of the
dressing and pop the other
slice of ciabatta on top.
Press down on the
sandwich to squash all
the layers together.
Wrap the sandwich in baking
parchment and tie it together
with a couple of pieces of string.
Place a heavy baking tray
on top of your sandwich
and top it with weights or
loaf tins filled with baking beans. Pop it
all in the fridge overnight or until you
are ready to eat it. Cut and serve in
slices for the perfect picnic snack.