Cut pumpkin in half and scrape out seeds. Brush with 2 tablespoons olive oil and place garlic in the cavity. Place onto greased baking tray cut side down. Bake in preheated oven for about 30 minutes until the pumpkin is soft.
Heat 4 tablespoons olive oil in a large saucepan until it almost smokes. Fry the sage leaves for about 1 minute until they are browned but not black. Drain on paper towels. Keep olive oil in the pan.
Allow pumpkin to cool slightly then scrape out pumpkin flesh.
Reheat olive oil in saucepan and saute onion until soft and translucent; about 8 minutes. Add thyme, diced sage and parsley. Saute for an additional 5 minutes.
Add pumpkin flesh and stock then cook for 25 minutes on low heat.
Puree soup and season with salt, pepper and vinegar.
Ladle soup into soup bowls and add some of the fried sage leaves and Gouda to each bowl. Serve immediately.