Vegetable Stock Concentrate
Wash and dry all produce. Preheat oven to 400 degrees. Peel and halve carrots, then cut into 2-inch long wedges. Strip leaves from thyme. Discard stems. Mince or grate garlic. Halve lemon.
Squeeze lemon juice into a large bowl. Whisk in garlic, thyme leaves, cumin, chili flakes (to taste), salt, pepper, and a large drizzle of olive oil. Add carrot wedges and toss to coat.
Spread carrots onto a baking sheet, keeping some dressing in bowl. Roast until lightly browned, 25-30 minutes. Toss halfway through.
Meanwhile, heat a drizzle of olive oil in a small pot over medium heat. Add couscous and toss until slightly fragrant, 1-2 minutes. Stir in 1½ cups water, stock concentrate, and a pinch of salt. Bring to a boil, cover, and reduce to a simmer. Cook until al dente, 10-15 minutes.
Pit, peel, and dice avocado. Toss in bowl with remaining dressing. Toss in roasted carrots, arugula, a drizzle of olive oil. Season with salt and pepper.
Divide Israeli couscous between plates. Top with salad. Garnish with pepitas and a dollop of sour cream.