Cook the quinoa: Preheat the oven to 400 degrees. In a small pot, bring 11/2 cups water, the stock concentrate, and a large pinch of salt to a boil. Once boiling, add the quinoa, cover, and reduce to a simmer for about 20 minutes, until tender.

Wash and dry all produce. Peel and finely chop the shallot. Mince the garlic. Finely chop the parsley. Thinly slice the mushrooms. Halve the bell peppers lengthwise before removing the core, seeds, and white veins

Drizzle the bell peppers with olive oil and season with salt and pepper. Roast on a baking sheet 10-12 minutes, until slightly softened.

Heat a drizzle of olive oil in a large pan over medium-high heat. Add the mushrooms. Cook, tossing, for 4-5 minutes, until golden brown. Add the shallot and garlic. Cook 2-3 minutes, until fragrant.

Add 1 Tablespoon vinegar, a drizzle of olive oil, the quinoa, and half the parsley to the pan. Cook, tossing, for 1 minute. Taste and season with salt and pepper. Spoon the quinoa into the bell peppers, then return to the oven 5-7 minutes, until the peppers are very soft.

Serve: Sprinkle the quinoa stuffed peppers with feta, pepitas, and the remaining parsley. Enjoy!