Bring a large pot of water with a large pinch of salt to a boil. Halve, peel, and mince the shallot. Mince or grate the garlic. Strip the thyme from the stem and roughly chop. Juice the lemon. Trim, halve and thinly slice the brussels sprouts into shreds.

Heat 1 tablespoon oil in a large pan over medium heat. Add the brussels sprouts and cook, tossing, for 3-4 minutes, until softened and slightly golden brown. Season with salt and pepper and set aside.

In the same pan, heat 1/2 tablespoon oil over medium-high heat. Add the mushrooms and cook, tossing, for 4-5 minutes, until golden brown. Season with salt and pepper and set aside.

Add the pasta to the boiling water and cook 8-10 minutes, until al dente. Drain, reserving 1/4 cup of the pasta water.

In the same pan you cooked the mushrooms in, heat another 1/2 tablespoon oil over medium heat. Add the garlic, thyme, and shallots to the pan and cook 30 seconds, until fragrant. Add the stock concentrate, 1 tablespoon butter, 1 tablespoon lemon juice, and 1/4 cup pasta water to the pan. Bring to a simmer for 4-5 minutes, until slightly thickened. Season with salt and pepper.

Toss the drained pasta into the pan with the sauce. Add brussels sprouts, mushrooms, and half the Parmesan cheese. Toss to combine.

Serve the pasta with the remaining Parmesan cheese on top and enjoy!