Fish In Foil With Potatoes, Mushrooms, Asparagus & Hollandaise

Step 1: Potatoes ... This is where a mandolin comes in handy. You really want these potatoes thin sliced. If you take your time; you can also cut them by hand. But, a food processor, slicer or mandolin really is best. As you prep everything else; add the potatoes to a bowl of cold water; this prevents them from browning. When ready to make the packets, remove them from the water; and set on a paper towel to dry.

Step 2: Mushrooms ... NOTE: I like to use a mix of wild mushrooms. Now, I can buy a wild mix right at my grocery store or farmers market; but, use what you like - and, always use what looks fresh. I have used a mix of button, cremeni, shitaki, porcini, and enoki, etc. Just use whatever mix you like.

Step 3: When, you buy a mix; they are usually trimmed and cleaned well. You just need to brush them off using a paper towel. Otherwise, you can buy them whole, trim and slice yourself. You want approximately 2-2 1/2 cups once they are sliced. And NEVER rinse your mushrooms under water.

Step 4: Asparagus ... You definitely don't want to use the pencil thin asparagus for this; you want thicker spears, so they don't over cook. And, make sure to trim the ends.

Step 5: Fish ... Make sure to take the fish out of the refrigerator to take the chill off; about 15-20 minutes, almost room temperature. Dry the fish with a paper towel; and, season each filet with half of the salt, pepper, and herb seasoning. If using salmon, make sure it is skinless.

Step 6: Packets ... To make 4 packets; you will need 4 large sheets of foil, about 16" square. Spray the center of the foil with a little non stick spray or a little olive oil; and, set the piece of foil in a large wide bowl or shallow rimmed dish. This is important - because when you add the wine to the packet, you don't want it to run out.

Step 7: For each packet (remember, you are making 4), so divide the ingredients between 4 servings. Add the potato slices and shallots in the center of the foil in a single layer; and, top with the remaining salt, pepper, herb seasoning, and 1 teaspoon butter. Set the fish, seasoned side up on top of the potatoes; then, add the sliced mushrooms and asparagus spears on top of each filet. Drizzle with 1 teaspoon olive oil over the top; then, add 3 tablespoons of wine around the fish. The bowl/dish prevents the wine from running out of the packet. Then, fold the packets up; each side; then twist or fold over the ends. Just so the wine doesn't leak out. Set the 4 packets on a cookie/baking sheet.

Step 8: Bake ... In a preheated 375 degree oven on the middle shelf. If using a thick piece of cod; they should take around 25-35 minutes; and, if using a thinner halibut; about 20-30 minutes; which is about the same for salmon. Cooking time on the grill is about the same; although, I like to cook 10 minutes on medium direct heat; and 20 minutes on medium indirect heat. Again, I do use a small sheet pan. Remember, these are times I find work best; however, the size, thickness of your potatoes, fish, etc can easily alter the time a bit.

Step 9: Hollandaise ... As the fish cooks; prepare your sauce. First, I like to warm up the blender, this really helps. Simply add very very hot tap water to the blender, let it set a few minutes, pour out the water; then, dry with a paper towel. While the blender is still warm, add the lemon juice and egg yolks to the blender; and puree until you get a smooth light creamy color. Melt the butter in the microwave or on the stove top until it is hot. Then, slowly drizzle in the hot butter - very slowly. The sauce should emulsify or 'thicken,' then, season with a little cayenne or hot sauce, mustard (optional); salt and pepper to taste. Personally, I like to add the mustard; but, that is completely optional.

Step 10: Once the sauce is made ... you can put it into a bowl and set it over a pot of simmering hot water. You can also put it in a thermos to stay warm. Or, if you made it ahead; just reheat it slowly on the stove, whisking often.

Step 11: Serve and ENJOY! ... Serve each packet on a plate, and open it up - be careful, there will be lots of steam. Then, drizzle a little of the hollandaise over the top. Don't forget the dill and chives as a garnish. I usually serve the extra sauce on the table; for those who want extra. A simple mix of greens and tomatoes; or roasted tomatoes, are a perfect side.

Step 12: It really is a elegant dish; and, perfect for that dinner with that 'special someone,' or to entertain with. Again. You can completely prepare the packets ahead of time; as well as the hollandaise. Makes it easy to entertain with.