Wash and dry all produce. Preheat oven to 450 degrees. Bring 11/2 cups water to a boil in a small pot. Once boiling, add brown rice, then cover and reduce to a simmer. Cook until tender, about 25 minutes.

Trim and halve Brussels sprouts lengthwise. Peel, then thinly slice carrot on a diagonal into 1/4-inch-thick slices. Strip rosemary, thyme, and parsley leaves from stems, keeping each herb separate from one another. Discard stems. Roughly chop all herbs. Halve lemon.

In a large bowl, toss together Brussels sprouts, carrots, cauliflower, thyme, and a large drizzle of olive oil. Season with salt and pepper.

Spread seasoned veggies out on a baking sheet and roast until tender, about 20 minutes. Toss halfway through.

Heat a drizzle of olive oil in a small pan over medium heat. Add rosemary, 1/2 cup water, and stock concentrate. Simmer until liquid has reduced by half. Add a squeeze of lemon and 1 TBSP butter. Continue simmering until thickened, about 3 minutes.

Fluff rice with a fork. Divide between plates, then top with roasted veggies. Drizzle the pan sauce onto veggies and garnish with parsley and pepitas.