Heat 1 tablespoon of olive oil over medium heat in a medium sauce pan. Add the onion and garlic. Cook until fragrant.
Add the orzo, ⅔ cup white wine, and 1 cup broth. Let cook covered for about 7 minutes. Once the liquid is absorbed, test the orzo. It should be tender. If it is not fully cooked, add broth ½ cup at a time. Let the liquid absorb and test again. Repeat until the orzo meets desired tenderness. Stir frequently to prevent burning.
Once the orzo is close to being done, add about 3 cups of the cooked butternut squash and ⅔ cups of broth in a food processor or blender and blend about 2 minutes, or until smooth.
Stir butternut squash puree, sage, and black pepper into the orzo. Stir well to incorporate. Let heat 2 to 3 minutes until warmed, stirring frequently.
Add ⅓ cup of feta cheese. Stir to incorporate. Add salt, if desired, to taste. Stir in half of the remaining cooked squash, reserving the rest for topping. Let warm another 2 to 3 minutes. Remove from heat.
Divide among 4 bowls and garnish with remaining roasted squash, additional feta cheese, and/or a sprinkle of herbs, as desired.