Step 1 Heat the oven to 375 degrees. Wash and dry the chicken. Halve or quarter it and season with 1 teaspoon salt and one-half teaspoon pepper, or to taste.
Step 2 Peel and cut the potatoes into wedges. Place them in a bowl and toss with three-fourths teaspoon each of salt and pepper, or to taste.
Step 3Place the chicken, skin-side down, in a roasting pan, and scatter the potatoes around it. Halve the lemons and squeeze them over the chicken and potatoes. Sprinkle over the oregano. Drizzle over the oil and water.
Step 4Roast the chicken for 20 minutes, then turn it skin-side up. Continue to roast for 40 more minutes. Increase the temperature to 400 degrees and continue to roast about 8 to 10 more minutes until the chicken is golden and crisp, and a thermometer inserted deep into the thigh reads 165 degrees.
Step 5Cool slightly before serving. Serve the chicken and potatoes together, spooning a little sauce over each serving.