Preheat oven to 400°F (200°C) and line two baking sheets.
Cook the brown rice according to package instructions.
Toss cauliflower and broccoli with half the olive oil, salt, and pepper. Spread evenly on one tray.
Toss chickpeas and carrots with remaining oil, salt, and pepper. Spread on the second tray.
Roast for 20–30 minutes, shaking trays every 10 minutes.
In a bowl, whisk together all dressing ingredients until smooth. Adjust water for consistency.
Assemble your Roasted Veggie Rice Bowls: add rice, greens, roasted veggies, and chickpeas.
Top with sesame seeds, drizzle tahini sauce, and finish with fresh lemon juice.