Preheat oven to 400 degrees. In a medium pot, bring 3 cups water, the brown rice, and a large pinch of salt to a boil. Cook 30-35 minutes, until tender. Drain.

Prep the vegetables: strip the thyme leaves off the stem, then roughly chop. Mince or grate the garlic. Trim and halve the Brussels sprouts, then thinly slice crosswise into shreds. Thinly slice the mushrooms.

Heat 1 tablespoon oil in a large pan over medium-high heat. Add the mushrooms to the pan and cook, tossing, until browned, 4-6 minutes. Add the shredded Brussels sprouts to the pan and cook, tossing, for 5 minutes, until softened. Add the thyme and garlic to the pan and cook 30 seconds, until fragrant. Season with salt and pepper.

Add 1/2 cup water and the stock concentrate to the pan and simmer until thickened. Remove pan from heat, then stir in the sour cream, 1 tablespoon butter, 1 tablespoon Dijon mustard, and half the Parmesan cheese.

Sprinkle the panko and remaining Parmesan and over the top of the Brussels sprout mixture, then place pan in the oven for 5-7 minutes, until golden brown. HINT: If you do not have an oven-proof pan, transfer the Brussels sprout mixture to a small (8x8”) baking dish before sprinkling with the panko and Parmesan.

Roughly chop the hazelnuts. TIP: toast the hazelnuts in a dry pan over medium-low heat until fragrant for more hazelnut flavor. Serve the Brussels sprout crumble on a bed of brown rice, sprinkled with hazelnuts. Enjoy!