Whisk lemon juice, olive oil, garlic, oregano, paprika, salt, and pepper in a large bowl.
Add chicken to marinade, toss, and marinate for 20 minutes or up to 24 hours.
Preheat oven to 400°F (200°C). Toss potatoes with olive oil, garlic powder, salt, and pepper; roast for 30 minutes, stirring halfway.
Cook chicken in a skillet over medium-high heat for 7-8 minutes per side until cooked through. Rest for 5 minutes, then slice.
Toss zucchini with remaining marinade, then cook in the same skillet over high heat for 5-7 minutes until tender. Assemble bowls with chicken, potatoes, and zucchini.
Notes
Feel free to customize with your favorite vegetables or herbs for added flavor.