Pare the potatoes to look like mushrooms: To make the "stem," insert a corer into each potato two-thirds from the bottom. Leave the corer in place. To make the "mushroom cap," take a paring knife and make a horizontal cut all around the potato to meet the corer. Carefully remove the bottom of the potato, then remove the corer, exposing the "stem."
In a large skillet, melt the butter and sauté/roast the potatoes, salt, and black pepper until the potatoes are lightly browned and tender. Steam the asparagus for 5 to 7 minutes or until tender-crisp. Keep warm.
Season the fillets with the salt and black pepper and grill over hot coals for about 5 minutes on each side or until cooked through.
Ladle 2 to 3 tablespoons Chardonnay Butter Sauce onto each plate and place 1 fillet on top of the sauce. At one end of each fillet, place the Dilled Berry Relish and the "mushroom" potatoes. Fan 5 asparagus spears by the potatoes and serve immediately.