Creamy, cheesy polenta acts as a bed for savoury, earthy, umami-packed mushrooms in this dish. A rich, glossy mushroom sauce and bright gremolata turn this fall dish into something you’ll crave all year round!
Roughly chop the mixed mushrooms, cutting them into approximately one-inch (two and a half centimetres) pieces. Separate the trimmings (about one-quarter) from the nicer bits (about three-quarters) and reserve separately – the trimmings for the Mushroom Sauce, and the nicer bits for the Roasted Mushrooms.
Heat olive oil in a large pot over medium-high heat.
Add onion, carrot, celery, and mushroom trimming. Cook until starting to brown, five to six minutes.
Add water, dried porcini, thyme, rosemary, and sage to the pot. Bring to a boil and remove from the heat.
Cover and let the stock steep for two hours.
Meanwhile, in a large, separate pot, combine the butter and flour and cook together, stirring often, to form a dark roux, 30 to 45 minutes.
Strain the stock into the roux a small batch at a time while whisking vigorously.
Bring stock-roux mixture to a gentle simmer and cook until smooth and thickened, eight to 10 minutes. Add tamari and browning sauce.
Season with salt and keep warm.
Heat a cast-iron pan over medium-high. Add oil.
Add mushrooms and cook until nicely browned 10 to 12 minutes.
Add butter, garlic, and thyme. Toss and cook for another three minutes.
Add tamari and season with salt and pepper.
Preheat the grill to high.
Brush the sliced focaccia with oil and season with salt and pepper.
Grill until charred and crispy on both sides, roughly two to three minutes per side.
In a small bowl, mix the chopped parsley, minced garlic, and lemon zest. Set aside.
Set a slice of Grilled Foccacia in the middle of a serving plate.
Top with roasted mushrooms and neatly spoon the mushroom sauce over top.
Garnish with gremolata and serve immediately. Enjoy!