Step 1: In a large skillet or Dutch oven, cook the diced bacon over medium heat until crispy and golden. Remove the bacon with a slotted spoon and drain on paper towels, leaving the rendered fat in the pan.
Step 2: Add 1 tablespoon of butter to the bacon fat. Sauté the minced shallots and garlic over medium-low heat for about 3-4 minutes until softened and translucent.
Step 3: Increase heat to medium. Add the Arborio rice to the pan and stir constantly for 2-3 minutes to toast the grains until the edges are slightly translucent.
Step 4: Pour in the white wine and stir until the liquid is almost completely absorbed by the rice.
Step 5: Begin adding the warm stock one ladleful (about 1/2 cup) at a time. Stir frequently and wait until the liquid is mostly absorbed before adding the next ladleful.
Step 6: Continue this process for 18-22 minutes until the rice is tender but still has a slight bite (al dente).
Step 7: Stir in the pumpkin puree and the chopped sage. Cook for another 2 minutes to allow the pumpkin to heat through and meld with the rice.
Step 8: Remove from heat and stir in the remaining tablespoon of butter and the grated Parmesan cheese until the risotto is creamy and glossy.
Step 9: Season with salt and black pepper to taste, keeping in mind the saltiness of the bacon and cheese.
Step 10: Serve immediately in warm bowls, topped with the reserved crispy bacon and extra Parmesan cheese.