2 cups balsamic vinegar
1 shallot, chopped
1/4 cup extra-virgin olive oil
2 cups coarsely chopped yellow onions
1 cup coarsely chopped carrots
1 cup coarsely chopped celery
2 bay leaves
3 cups dry red wine
8 cups roasted chicken stock, or veal or rabbit stock
6 black peppercorns
4 tablespoons unsalted butter
1 1/2 cups heavy cream
3 cups cold water
Pinch of sea salt, preferably gray salt
1 cup fine-ground polenta
1/2 teaspoon freshly grated nutmeg
1/2 cup shredded fontina cheese
1/4 cup freshly grated Parmesan cheese
3 tablespoons extra-virgin olive oil, plus more if needed
10 ounces cultivated or wild mushrooms such as shiitakes, chanterelles, and morels, cleaned and trimmed (stem shiitakes)
Pinch of sea salt, preferably gray salt
Freshly ground black pepper
1/2 teaspoon minced garlic
1/2 teaspoon minced fresh thyme
1 teaspoon minced fresh flat-leaf parsley
1 cup freshly grated Parmesan cheese
*6, half-pint French glass canning jars with an attached lid.
For the balsamic sauce: In a small saucepan, combine the vinegar and shallot. Bring to a simmer over medium heat and cook until reduced by half, about 10 minutes. (Watch this because at the end, the reduction process speeds up.) Remove from the heat and set aside.
In a large saucepan, heat the olive oil over medium-low heat and add the onions, carrots, celery, and bay leaves. Cook, stirring occasionally, until the vegetables are a deep brown, about 20 minutes. Add the red wine and reduce the heat to medium-low. Cook to reduce by half, about 10 minutes.
While the vegetables are cooking, pour the chicken stock into a stockpot, add the peppercorns, and cook over high heat until the liquid is reduced by half, about 15 minutes. Pour the reduced stock into the pan with the red wine and vegetables. Cook for 5 minutes over medium heat. Add the reduced balsamic vinegar. Remove from the heat, stir in the butter, and set aside.
For the polenta: In a large, heavy saucepan, combine the cream, water, and pinch of salt. Bring to a boil over high heat and then reduce the heat to medium. Gradually whisk in the polenta in a slow, steady stream. Whisk until the liquid boils again and the grains are suspended in the liquid. Keep whisking so the polenta doesn’t scorch. Once it comes to a simmer, switch to a wooden spoon and stir every few minutes until the polenta is creamy without any hint of grittiness, 15 to 20 minutes. Remove from the heat and stir in the fontina and the Parmesan.
For the mushrooms: Heat a large sauté pan or skillet over high heat, add the 3 tablespoons oil, and heat until it shimmers. Add the mushrooms but no more than 2 deep anywhere in the pan; if you pile them on, they will steam instead of browning. Cook the mushrooms in two pans if you have to. Mushrooms over heat can be temperamental: don’t stir them, don’t salt them, and don’t turn them until the bottom layer is brown, about 2 minutes. Reduce the heat to medium and season with salt and pepper. When the mushrooms have begun to turn brown, stir in the garlic and sauté until the garlic shows a light brown color. Add thyme, and listen to it crackle in the pan. Add the parsley and toss. Remove from the heat and set aside. You can cook the mushrooms up to 1 hour before serving.
For the Parm crostini: Preheat the oven to 425°F. Line a baking sheet with a silicone mat or parchment paper. If you have them, place six 3-inch ring molds on the prepared pan. Inside each ring mold, evenly spoon about 2 tablespoons grated Parmesan. (If free-form, make 6 mounds of Parmesan about 2 inches apart, and spread into thin, even rounds.)
Slide the pan into the oven and bake until the Parmesan is melted into disks that are just beginning to brown, 3 to 5 minutes. Store these stacked in an airtight container for up to 3 days.
To serve: Spoon 1/2 cup polenta into each of six half-pint French glass canning jar with an attached lid. Place one Parmesan crostini on top, either neatly resting on the surface of the polenta or slid into the surface at an angle. Divide the mushrooms among the jars. Serve the balsamic sauce at the table and let guests pour a few tablespoons of it per serving. Pour any remaining sauce into small creamers or pitchers so guests can pour on more sauce as they wish.
The free-form crostini won’t fit as smoothly on the top of your polenta as the ring-molded ones, but just angle them in or trim to fit and they’ll be just as good.
Consider the polenta recipe a template; you can substitute any liquid for the cream. Try it with chicken stock, tomato sauce, or vegetable juice.
The polenta is best made an hour or two before you plan to serve it; cover it with a sheet of waxed paper, smoothed onto the surface of the polenta. If you’d like to make it the day before, you might need to add some liquid when you heat it. Definitely make the balsamic sauce the day before, so you can chill it overnight and lift off the fat; then rewarm and add a final touch of butter just before serving. The Parm crostini can be made a day or two ahead of time as well. They’re great in Caesar salads if you want to make a double batch. You can use 3-inch ring molds for perfect symmetrical disks, or just wing it and go free-form.