Season the Chicken: Pat the chicken leg quarters dry with paper towels and place them in a large bowl. Drizzle with olive oil and sprinkle the paprika, garlic powder, onion powder, black pepper, salt, and dried parsley evenly over all sides, rubbing gently to coat.
Preheat the Oven: Set your oven to 400°F and allow it to preheat for about 10 minutes while you prepare the fries.
Roast the Chicken: Arrange the seasoned chicken pieces skin-side up on a large baking sheet lined with foil or parchment paper, spacing them about 2 inches apart. Roast for 30-35 minutes until the skin is crispy and golden and the internal temperature reaches 165°F at the thickest part of the thigh.
Prepare the Fries: While the chicken roasts, cut the potatoes into fries and fry them in vegetable oil heated to 350°F for 8-10 minutes until golden and crispy, stirring occasionally. Alternatively, toss with oil and bake at 425°F for 25-30 minutes, stirring halfway through.
Make the Sauce: In a small bowl, whisk together the Greek yogurt, minced garlic, chopped fresh parsley, and lemon juice until smooth and well blended. Season with a pinch of salt and black pepper to taste.
Arrange the Base: Place a generous portion of crispy fries in the center or to one side of a large serving plate or platter.
Add the Chicken: Position the roasted chicken leg quarters alongside or slightly overlapping the fries, skin-side up for visual appeal.
Layer the Fresh Vegetables: Arrange the sliced tomatoes and red onion around the chicken and fries for color and freshness.
Serve the Sauce: Dollop the garlic herb yogurt sauce on the side or drizzle lightly over the chicken, allowing diners to add more as desired.