preheat oven to 400F
In a large mixing bowl toss the squash and carrots in oil. Then add all the spices and toss more till evenly coated.
Spread the vegetables over 2 roasting pans and roast for 40 minutes
When there are about 8 minutes left of roasting time for the vegetables sautee the onion and garlic in a large soup pot til the onions are soft and fragrent
Add the vegetables to the pot along with the vegetable stock. Bring to a boil, reduce to medium low, cover and simmer for 10 minutes.
Remove the soup from the heat and blend with a hand emulsifier until fully smooth. Slowly stir in the milk then return to heat and simmer on low covered for 20 minutes
remove the soup from the heat 5 minutes before serving. Just before serving stir in the lemon juice. You want the soup to have cooled some before adding the lemon juice to prevent curdling.