In your favorite soup pot over medium heat, melt the butter and sauté the onions until softened. Add the apples and squash and cook until coated with the oniony goodness, about three minutes.
Add chicken stock and rosemary and bring to a simmer.
Add thyme.
Reduce heat to medium and simmer covered about 30 minutes. Vegetables should be very tender.
Remove from heat and puree soup until smooth.
Stir in half-and-half and season with salt and pepper to taste. Sprinkle rosemary and thyme on top for garnish if desired.