1. Remove giblets from chicken& discard (or use to make giblet gravy).
2. Place chickens into a large shallow roasting pan.
3. Tuck onions into cavity; squeeze lemon over chicken& tuck into cavity.
4. Peel& seed squash; cut into 2 inch cubes.
5. Peel carrots& cut into 2 inch rings.
6. Peel& quarter potatoes.
7. Scatter these vegetables around the chickens.
8. Pour broth over top of everything.
9. Bake in the center of a preheated 350F oven for 35 minutes.
10. Meanwhile, slice off dark green portions of leeks, leaving the pale green& white portion intact& slice in half lengthwise.
11. To wash away the sand, fan the layers under cold running water.
12. Seed peppers& cut into cubes.
13. Remove chicken from oven, stir vegetables& baste the chicken.
14. Scatter leeks& peppers around the chicken and sprinkle with salt& pepper.
15. Continue roasting, basting 2 or 3 more times, for another 35 to 45 minutes.
16. Remove chickens to a large platter; remove lemon& onions from cavity& discard.
17. Pile roasted vegetables around the chickens& serve.