Preheat the oven to 400°F.
Pat the chicken breast dry and season generously with cumin, paprika, garlic powder, salt, and pepper.
Place the chicken on a baking tray lined with parchment paper and roast in the preheated oven for 20-25 minutes, or until the internal temperature reaches 165°F.
While the chicken is roasting, prepare the salad by chopping mixed greens, tomato, cucumber, red onion, and green bell pepper into bite-sized pieces.
In a small bowl, whisk together olive oil, lemon juice, and a pinch of salt and pepper to create the dressing.
Once the chicken is cooked, let it rest for 5 minutes before slicing it into strips.
Toss the chopped vegetables with the dressing in a large bowl.
Plate the salad and top with the sliced spiced roasted chicken. Serve immediately.