1.In a food processor blend Parmesan cheese and keep aside.
2.Pulse the basil, walnuts, garlic along with a little salt and pepper.
3.Drizzle olive oil and mix well.
4.Transfer in a bowl and add Parmesan cheese and mix.
5.Take two slices of sour dough bread.
6.Spread pesto on one of them.
7.Put the both the cheese on the pesto.
8.Top with turkey, black forest ham and spinach.
9.Cover with the bread slice, butter both the sides and grill in on the griddle to make sandwich.
Store the pesto sauce in a bowl pour a good amount of olive oil and keep it in the refrigerator.