Halibut with potatoes

1 -1 1/2 lb halibut fillet 2 tablespoons butter (melted) 1 tablespoon canola oil or 1 tablespoon olive oil 2 cups o'brien frozen potatoes (diced) 1 (9 ounce)[...]

2 tablespoons butter 1 large fennel bulb , trimmed, halved and thinly sliced cross-wise 1/2 cup sliced shallot 2 tablespoons all-purpose flour 1 1/2 cups[...]

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,[...]