Using a food processor with a grating disc, grate the butternut squash. You can also use a cheese grater.
Combine the shredded butternut squash, flour, eggs, garlic, sage, pepper and nutmeg in a large bowl.
Preheat oven to 250°F and place a wire rack on top of a baking sheet. Pour in about ¼ inch of oil into a large skillet and heat over medium-high heat. Scoop up ¼ cup of the butternut squash mixture per fritter and drop into skillet. Use a spatula to flatten into discs. When the edges of the fritters are brown and crispy, about 3-4 minutes, flip. Cook for another 5 minutes or until browned.
Transfer cooked fritters to a paper towel-lined rack to drain and then put on wire rack in oven to keep warm while you cook the remaining fritters. Serve immediately.
If the mixture hasn't come together, add 1 tablespoon of flour at a time to get desired consistency.
If you don't have fresh sage, use 1 teaspoon of dried sage. It is much stronger so you need to use less.
Once you add the mixture to the oil, don't move them for 4 minutes before flipping so they create a crispy exterior.
Add a dollop of goat cheese, yogurt or sour cream for additional flavor.