Heat a large skillet over medium heat. Add olive oil and butter to pan; swirl to coat.
Add onions and bacon; cook 4-5 minutes till bacon is crispy and onion tender. Stir in rice, and cook for 1-2 minutes, stirring constantly.
Increase heat to medium-high and add wine and stir. Add stock ½ cup at a time, stirring constantly until each portion of stock is absorbed before adding the next. With the last portion of stock stir in the pumpkin and sage.
Remove from heat and add the cheddar and Parmesan.