1. 1. In a mixing bowl, whisk together olive oil, lemon juice, Dijon mustard, minced garlic, dried oregano, smoked paprika, salt, and black pepper. Add the chicken to the marinade, ensuring each piece is well-coated. Allow to marinate for at least 30 minutes or up to 2 hours.

2. 2. Preheat your oven to 400°F. Toss the diced sweet potatoes with olive oil, smoked paprika, garlic powder, salt, and cayenne pepper. Spread in a single layer on a baking sheet and roast for 25-30 minutes, flipping halfway through.

3. 3. Preheat your grill or grill pan over medium-high heat. Grill the marinated chicken for 5-7 minutes per side until the internal temperature reaches 165°F. Let rest for 5 minutes before slicing.

4. 4. To assemble the bowls, divide the cooked quinoa or brown rice and mixed greens among serving dishes. Top with roasted sweet potatoes, sliced grilled chicken, avocado, feta or goat cheese, and pumpkin seeds or almonds. Drizzle with tahini dressing if desired.