Preheat your oven to 400°F.
Pound the chicken breast to an even thickness. In a small bowl, whisk the egg white. Dip the chicken in the egg white, then coat it evenly with panko breadcrumbs seasoned with a pinch of salt and pepper.
Place the chicken on a baking sheet lined with parchment paper and bake for about 18-20 minutes until the internal temperature reaches 165°F, turning halfway for even crisping.
While the chicken bakes, chop the broccoli, carrot, and red bell pepper into bite-sized pieces. Toss them with olive oil, salt, and pepper, and roast on a separate baking sheet in the oven for 15 minutes.
Prepare the lemon-tahini dressing by mixing the tahini and lemon juice together. Add a small splash of water if needed to achieve a drizzleable consistency. Adjust seasoning with salt and pepper.
Warm the cooked quinoa if necessary. To assemble the bowl, layer the quinoa as a base, add the roasted vegetables, and slice the baked chicken into strips. Drizzle the lemon-tahini dressing over the bowl.
Serve immediately and enjoy your balanced, nutrient-packed meal.