Heat the olive oil in a large heavy-bottomed saucepan over medium-high heat. Add the butternut squash and saute until just starting to soften, 5 to 7 minutes. Add the garlic and onions and saute until fragrant and translucent, 2 minutes longer. Add the orzo and continue cooking another 2 minutes, stirring occasionally. Pour in the wine and cook until absorbed.
Gradually add the chicken broth while stirring. Bring to a simmer, cover and cook until the liquid is almost absorbed and the orzo is tender, 8 to 10 minutes. Remove from the heat.
Stir in the Parmesan, half-and-half and sage. Season with salt and pepper and serve warm.