Method

1. Rinse the chicken and pat dry.
2. Set in a large roasting pan. In a bowl, combine the olive oil, butter, and salt.Coat the chicken, inside and outside, with the mixture.
3. Stuff the thyme sprigs and shallots into the cavity.
4. Remove the wing tips and truss or tie the legs together.
5. Position the bird, breast side down, in the pan and let come to room temperature.
6. Preheat the oven to 425 degrees F (220 degrees C).
7. Cut the squashes lengthwise into quarters or eighths and remove the seeds.
8. Place the pan in the oven and roast the chicken until lightly browned, 15-20 minutes.
9. Turn the bird and pour lemon juice and water into the pan.
10. Add the squashes, skin side down, and brush with the pan juices.
11. Reduce the oven temperature to 400 degrees F (200 degrees C).
12. Continue to roast, brushing the chicken and the squashes with the pan juices every 15 minutes and adding water if the pan is dry, until an instant-read thermometer inserted into the thickest part of the thigh away from the bone registers 165 degrees F (74 degrees C), 50-60 minutes.
13. Transfer the chicken and squashes to a warmed platter.
14. Place the roasting pan over medium-high heat, and stir to scrape up any browned bits on the pan bottom.
15. Pour the pan juices through a fine-mesh sieve placed over a serving bowl, and skim off any fat from the surface.
16. Carve the chicken and serve with the squashes. Pass the pan juices at the table.