3-1/2 Tablespoons unsalted butter
3 large leeks, white and tender greens – split, thinly sliced crosswise and thoroughly rinsed (about 3 cups)
2 cups mushrooms, thinly sliced (about
5 ounces)
Salt & freshly ground black pepper
2 Tablespoons fresh flat leaf parsley, finely chopped
1-1/2 ounds red potatoes, peeled, and sliced very thinly
1-1/2 cups gf chicken stock
1-1/2 pounds cod filet, in one piece
2 teaspoons olive oil
1 large plum tomato, diced