Preheat oven to 400°F. Line a rimmed baking sheet with parchment paper. Toss squash with oil and season with salt and pepper right on the baking sheet.
Roast squash for 25 to 35 minutes, until very tender and golden-brown.
Melt butter in a heavy-bottomed pot, preferably a Dutch oven or braiser, over medium heat. Add shallot and cook for 2 to 3 minutes, until softened. Add orzo and stir to coat. Stir in broth and increase the heat to high. Heat to a boil. Reduce to low and cook, uncovered, stirring frequently, for 8 to 10 minutes, until the orzo is tender, but still slightly more liquidy than a risotto.
Stir in cheese, lemon juice, and half of the roasted squash. Continue stirring until the cheese has melted and the orzo has a nice risotto consistency. Add a splash of broth if it gets too thick. Season to taste with salt and pepper. Divide the risotto among 4 bowls and top with remaining roasted squash, the basil and additional grated Parmesan cheese.
To add protein to the recipe, make chicken meatballs. Combine 1 pound of ground chicken with ⅓ cup breadcrumbs, 1 large egg, the zest of 1 lemon, ¼ cup chopped basil, and ¼ cup grated Parmesan cheese. Roll the mixture into 10 meatballs and cook on the baking sheet with the squash for last 12 minutes of the roasting time (or until done).
If butternut squash is not in season, roast zucchini instead. Cut it into ½-inch thick half circles and roast for 20 minutes, the same way.
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.