Preheat the oven to 180°C. Peel the root vegetables and cut them into large chunks or wedges.
Place the chicken in a large backing tray. Put the vegetables around the chicken.
Lightly smash the garlic cloves with a tenderiser and tuck these between the chicken and veggies.
Scatter the thyme leaves on top, then drizzle with olive oil and squeeze the juice of the lemon wedges juice all over. Put the lemon wedges in the tray then season everything with salt and pepper.
Bake for 40-45 minutes, turning and basting the chicken and veggies a couple of times.
When the vegetables are tender, and the chicken is golden and properly cooked through, take the tray out of the oven.
Serve the chicken and veggies with their jus from the pan.