Wash and dry all produce. Preheat oven to 300 degrees. Trim, then thinly slice mushrooms. Mince garlic. Halve, peel, and mince shallot. Strip thyme leaves from stems; discard stems. Roughly chop leaves. Finely chop parsley. Slice half the polenta into 1/2-inch rounds (use the rest as you like).

Heat a thin layer of olive oil in a large pan over medium-high heat (we used 1 TBSP). Add polenta and cook until browned and crisp on surface, 2-3 minutes per side. Transfer to a baking sheet and place in oven to keep warm.

Melt 1 TBSP butter in same pan over medium-high heat. Add mushrooms and cook, tossing, until tender, 5-6 minutes. Season with salt and pepper. Remove from pan and set aside.

Heat a drizzle of olive oil in same pan over medium heat. Add shallot, thyme, and garlic. Cook until softened, 2-3 minutes. Pour in 1/2 cup water and stock concentrate. Bring to a boil, then lower heat and let simmer until reduced to a saucy consistency, 2-3 minutes. Remove pan from heat. Stir in sour cream and mushrooms. Season with salt and pepper.

In a medium bowl, toss arugula, pine nuts, 2 tsp balsamic vinegar (we sent more), and a large drizzle of olive oil. Season with salt and pepper.

Divide polenta between plates. Spoon over gravy. Sprinkle with Parmesan and parsley. Add salad to the side and serve.