Cut squash into 2 pieces with skin on. Place in large soup pot. Peel potatoes, cut to 1 inch pieces and add to squash. Cover vegetables with stock and bring to boil.

Reduce heat, cover and simmer for 20 minutes. Then add butter cut in pieces, 1 Tbsp dill, salt and pepper. Remove from heat.

Puree soup in blender or food processor until smooth. Return it to soup pot and heat through, stirring in remaining 2 Tbsps dill. Sprinkle on green onion before serving.