Prep the ingredients: Wash and dry all produce. Preheat the oven to 300 degrees. Thinly slice the mushrooms. Mince or grate the garlic. Halve, peel, and mince the shallot. Strip the thyme off the sprigs, then roughly chop the leaves. Finely chop the parsley. Slice half the polenta into 1/2-inch thick slices (save the rest for another day!).

Cook the polenta: Heat a drizzle of olive oil in a large pan over medium-high heat. Once hot, sear the polenta for about 1 minute per side, until golden brown. Transfer to a baking sheet and place in the oven to keep warm.

Cook the mushrooms: In the same pan, heat 1 Tablespoon butter over medium-high heat. Add the mushrooms to the pan and cook, tossing for 5-6 minutes, until golden brown. Season with salt and pepper, then remove from the pan and set aside.

Make the mushroom ragout: Heat another drizzle of olive oil in the same pan over medium heat. Add the shallot, thyme, and garlic to the pan and cook for 2-3 minutes, until softened. Add 1/2 cup water and the vegetable stock concentrate to the pan. Bring the ragout to a boil, then reduce to a simmer until reduced and thickened for 2-3 minutes. Remove the pan from heat, then stir in the sour cream and mushrooms. Season to taste with salt and pepper.

Dress the arugula salad: Toss the arugula in a medium bowl with 1 Tablespoon balsamic vinegar and a drizzle of olive oil. Season to taste with salt and pepper.

Plate and serve: Plate the crispy polenta cakes and top with the mushroom ragout and a sprinkle of parmesan and parsley. Serve the tangy arugula salad to the side and enjoy!