In a medium saucepan, heat olive oil over medium heat. Add the sage leaves and fry until lightly browned.
Add the pumpkin puree, cream and chicken stock. Stir until combined, then add salt, pepper, sugar and nutmeg.
Gently simmer mixture until slightly thickened, about 10-15 minutes.
While sauce simmers, brown sausage in a large frying pay over medium heat. Once browned, remove from pan onto a paper towel lined plate.
Roll the pizza dough into a thin circle (does not have to be perfectly round). Top dough with a thin layer of sauce and sausage.
Place pizza on a pan (I used a pizza stone) and bake for 5-7 minutes, then add crumbled goat cheese and half of the Parmesan cheese. Return to oven and bake for another 10 minutes.
Remove from oven and add remaining Parmesan cheese and serve.