While the squash roasts, make the orzotto. Heat the remaining 1 tablespoon oil in a deep skillet (braiser or Dutch oven works great) set over medium heat. Add the onion, remaining 1/2 teaspoon salt, and black pepper and cook, stirring, until the onions is translucent, about 3 minutes.
Add the orzo and toast, stirring, 1 to 2 minutes. Add the garlic, stir, and cook for about 1 minute more. Add the wine and cook, stirring, until it has reduced by about half, about 1 minute.
Reduce the heat to medium-low. Add the thyme bundle, bay leaf, and 1 cup of the broth. Cook, stirring often, until the orzo has absorbed all of the liquid, about 4 to 5 minutes. Continue adding the broth, 1 cup at a time, allowing the orzo to absorb the liquid before adding the next cup. You will use 3 1/4 cups of broth total for the orzo. Cook, stirring often, until the orzo is al dente, about 10 minutes more. Remove from the heat.