Lamb Lasagna

Ingredients

12 lasagna sheets ( ready made)
1 kg lamb mince
1 onion diced
1 teaspoon garlic paste
1 teaspoon ginger paste
2 red chillies minced
1 teaspoon cumin powder
1 teaspoon salt
3 tablespoon oil
2 tablespoon tomato paste
1 tin crushed tomato or fresh 6 ripe tomatoes
1/2 cup chopped coriander
1/2 cup chopped spring onion ( optional)
1/2 water

White sauce
1 litre full cream milk
1 diced onion
5 cloves
3 bay leafs
2 tablespoon oil
50g butter
1/2 cup flour
125 g Parmesan cheese
1 cup grated pizza cheese