Preheat oven to 450 degrees.
Cut each chicken breast into 4-5 even-sized strips.In a large bowl add the chicken pieces, lemon juice from one whole lemon, 4 minced garlic cloves, 1 teaspoon salt, pepper, and paprika, and 2 tablespoons olive oil.
Mix together well and set bowl aside while you prepare the veggies.Rinse beans, snip off the end with the hard nub/stem, and place them in another large bowl. The other end should have a dainty little tail that is soft and thin and doesn't need to be removed.Chop one large yellow onion and add to the beans.Rinse (and scrub if needed) the baby potatoes and add to the veggie bowl.Stir in one 15-ounce can of petite diced tomatoes, juice from half a lemon, oregano, parsley, 1 teaspoon of salt and pepper, and 2 tablespoons olive oil.
Pour the mixture onto a large baking sheet (you may want to line it with parchment paper or tin foil), add the chicken pieces (spaced evenly throughout the pan), some lemon slices, 4 thinly sliced garlic cloves, about a dozen pitted Kalamata olives, and roast at 450 degrees for 20 minutes.Pull the pan out from the oven but don't remove. Crumble 4 ounces of feta cheese and sprinkle onto the sheet pan and continue to cook for 5 more minutes, or until the chicken reads 165 degrees with a meat thermometer.
Serve while it's hot and garnish with chopped parsley.