If you're roasting two chickens at once, just use a roasting pan big enough for the extra one while still leaving room for the potatoes.
1.5 kg chicken
2 garlic cloves, squished
2 tbsp lemon juice
1 tbsp olive oil
1 tsp dried Italian herb seasoning, crumbled (or any other herb mixture you like)
1 tsp salt
1/4 tsp black pepper
6 medium potatoes, peeled, quartered and steamed or boiled until tender
Preheat the oven to 400°F (190°C).
Wash the chicken well, inside and out, and pat it dry with paper towel. Some kids may enjoy doing this—it gives them the rare opportunity to examine the (slightly gross) anatomy of a chicken in gory detail. Just make sure they wash their hands thoroughly afterwards.
In a small bowl, combine the squished garlic with the lemon juice, olive oil, Italian seasonings, salt and pepper. With a pastry brush, spread this mixture all over the washed-and-dried chicken—inside and out. Place the chicken in a shallow roasting pan, leaving room for the potatoes.
Roast uncovered for 20 minutes, until the juices begin to accumulate on the bottom of the pan. Brush the chicken with the drippings, then add the cooked potatoes to the pan, stirring gently to coat them. If there's not enough liquid to coat the potatoes, drizzle them with 1 tbsp/15 mL vegetable or olive oil. Continue roasting for another 45 minutes to 1 hour, or until the chicken is golden brown and well done (a leg should move easily when you jiggle it), and the potatoes are nicely overdone (baste them once or twice with the liquid from the pan).
Remove from the oven, carve the chicken and serve hot. (If you've roasted a second chicken, let it cool slightly, then refrigerate.)