Cube the fish, sprinkle with lime juice and set aside.
Mix together the spinach, eggs, sour cream, basil, green onions, garlic and cashew nuts, also add the zest of the lime.
Add seasonings to taste.
Brush a 9 inch round baking tin with olive oil, a loose bottom or springform pan will make it easier to remove the pie after baking.
Brush a sheet of phyllo with olive oil, line the tin, sprinkle with some breadcrumbs, repeat with all the sheets overlapping each time and using the breadcrumbs, you will have lots of pastry hanging over the side of the tin.
Drain the fish, mix gently with the spinach mixture and pour in the pastry lined tin.
Top with the cheese and then the tomatoes.
Roll the overhanging pastry up and over the edge of the tin, ending up with a tight roll all the way around the pie but on the inside of the tin, then brush the pastry roll with olive oil.
Bake for 30-35 minutes, let stand for 5 minutes and remove from the tin.