While I was studying at Le Cordon Bleu in London (too many years ago now to admit), I lived in a flat near Hammersmith with two charming Brits, both named William. Will #1 and I have connections that run deep: our grandparents were friends, as are our parents, and now the two of us. While both Williams were equally happy to devour the results of my daily practicals at Le Cordon Bleu, Will #1 shared my interest in cooking and would occasionally make supper for the three of us, much to my delight.
His meals typically consisted of simpler fare, like fat, juicy sausages roasted right in the pan with root vegetables, but every once in while he’d whip up his piece de resistance: Portobello mushroom caps topped with a rich, savory mixture of cream cheese, herbs, caramelized shallots and bacon, and then roasted. I can’t remember where he got his inspiration, but it doesn’t really matter. In my house, as well as in my parents’ (for whom he made these seductive mushrooms on a visit to the U.S. a few years ago), they’re simply called “Will’s Mushrooms.”
The following recipe is my best effort at replicating Will's mushrooms. They're easy to make, but quite rich. You’ll want to serve one in place of a piece of meat or fish, perhaps accompanied by a green salad and a glass of wine. —Merrill Stubbs
Heat the oven to 375 degrees. Using a damp towel, gently wipe the mushroom caps clean. Arrange them with their gills down on an ovenproof rack set on top of a rimmed baking sheet. Bake the mushrooms for about 15 minutes, until they start to shrink and become tender, releasing a good amount of liquid onto the baking sheet below. Carefully remove the mushrooms from the oven and pour off the liquid, wiping the baking sheet dry. Flip the mushroom caps over and arrange them on the baking sheet again. Turn the oven up to 475 degrees.
Put the bacon in a small skillet over medium heat. Cook, stirring occasionally, until the bacon has rendered most of its fat and starts to become crisp, about 5 minutes. Add the shallot and continue to cook, stirring frequently, until the shallot is translucent and lightly caramelized, another 5 to 7 minutes. Using a slotted spoon, transfer the bacon and shallots to a medium bowl, discarding the bacon fat in the pan.
Add the rest of the ingredients to the bowl and stir gently to combine. (You probably won’t want to add any salt, but now’s the time to taste just in case.) Top each mushroom cap with about a quarter of the mixture, smoothing it so that it almost reaches the edges. Return the mushrooms to the oven and bake until the cheese starts to brown and bubble, 10 to 15 minutes. Let the mushrooms cool for a few minutes before serving.