Preheat oven to 400 degrees.
In a 9 x 13 inch baking dish, place onions and pumpkin (or squash). In a medium bowl, stir together peanut butter, half of the salt and half of the cayenne pepper. Gradually stir in hot chicken broth, melting the peanut butter. Stir in half of the lemon juice. Pour over the pumpkin and onions.
Place chicken on top of the vegetables. Sprinkle chicken with remaining salt, cayenne pepper and lemon juice. Sprinkle black pepper over chicken.
Bake for 1 hour, until pumpkin is tender and fork can be inserted in chicken with ease. Sprinkle with peanuts.
