Halibut Casserole

4 medium potatoes (unpeeled) 1 -1 1/2 lb halibut 1 teaspoon salt pepper 1/2 teaspoon sage 3 tablespoons butter 3 tablespoons flour 1 1/2 cups milk 1 lemon,[...]

2 tablespoons extra virgin olive oil 1 medium onion , chopped 2 garlic cloves , minced 1 (14 ounce) can chopped tomatoes , with juice kosher salt & freshly[...]