Black trumpet potato puree (think dried-mushrooms pureed into mashed potatoes) came from a dish I’d heard about when I was moonlighting as the stylist on Lenny Russo’s cookbook. Over the course of the eight month project, photographer Tom Thulen and I would work off a list of dishes from different sections each week, chosen by the powers that be (publisher). Mushroom potato puree (maybe because it comes in edible shades of brown and grey?) wasn’t chosen.
I’d made a few of the dishes in the manuscript for restaurant service before we starting working on the book, but I’d never made mushroom flavored taters, so I made a point to, sometime (6 years later). The original recipe called for mushroom duxelles, but I thought that making a really strong one with a thick puree of dried wild mushrooms could be really good, especially strong ones like black trumpets that love dairy, butter, and all the creamy smooth things.
I ended up marrying two recipes here: Chef Russo’s recipe, and the world-famous pommes de terre Robuchon, the latter of which I was taught how make to spec from a chef de partie who worked at Robuchon in Vegas. Quick aside, one secret to Chef Robuchon’s world-famous potatoes is that they’re made from…frozen French potato pearls, which ensures a consistent product year round that tastes the same, at the same time, in Vegas as it does in Paris.
To make my mushroom-lovers version here, you infuse the dried mushrooms into a bunch of cream and butter, puree it silky smooth, then use it to flavor some freshly cooked and rice potatoes.
It’s ultra rich and trumpety, good anywhere you’d have mashed potatoes, but especially meat, preferably roasted. It doesn’t include anywhere near the amount of butter real Robuchon potatoes call for, but it’s rich enough for me.
Use a ricer
This is really straightforward, but, you must use a ricer here. A foodmill will ruin a puree of potatoes with it’s circular motion, which activates the potato starch, making them feel like glue in your mouth.
Using other dried wild mushrooms
Feel free to use your favorite dried wild mushrooms here. Dried chanterelles are a great swap out for the trumpets, and keep the light color of the potatoes. Other strongly flavored mushrooms like porcini would be good too.
Black Trumpet Potato Puree
- 40 oz russet potatoes
- 1 oz dried black trumpets mushrooms
- 1.5 cups water
- 1 cup heavy cream
- 1 small shallot 2 oz
- 1 large clove garlic grated or minced
- 1 teaspoon salt plus more to taste
- 4 oz unsalted butter
- Fresh slices chives or green onions to garnish
- Cover the black trumpets with the water and rehydrate for 15 minutes. P
- eel the potatoes, then half and cut into 1 inch pieces. Bring the potatoes to a simmer using a pot of cold water, then turn the heat to low and cook until very tender, then drain very well and pass through a food mill into a mixing bowl while still hot. Cover the potato bowl with cling film and put in a warm place until needed.
- Meanwhile, agitate the mushrooms in the water to remove grit, then lift the mushrooms out of the water. Strain the liquid slowly, discarding the last tablespoon or two since any grit will be concentrated there. Reserve the mushrooms and liquid separately.
- Sweat the shallots, (grate the garlic into the pan now), in 2 tablespoons of the butter until translucent, then add the mushrooms and sweat for a few minutes more. Add the black trumpet liquid and reduce until the pan is nearly dry, then add the cream and salt, bring to a simmer, then turn down the heat and reduce for 5 minutes more on medium-low.
- Pour the trumpet cream into a highspeed blender like a vitamix, or a food processor in a pinch, and puree until very smooth, using the accelerator attachment to the blender if necessary to get the blades moving, dropping in the remaining butter, emulsifying to a smooth paste. Pour the mushroom cream into the still hot riced potatoes, combine, double check the seasoning for salt and adjust until it tastes good to you.
Plating as pictured
- To get the pattern on the potatoes as pictured in this post, which is how the potatoes are served at Robuchon (or at least how I was taught) take a knife with a length equal to the radius of the dish you will serve the potatoes in, put the potatoes in the dish, and smooth out the top with the blade of the knife. It takes some practice, and will frustrate most people, but you can always smooth out the top and start over if the pattern isn’t to your liking. Clean the rim of the dish with a damp towel after you're pleased with the patter.