Preheat oven to 500 F (220 degrees C).Peal and clean the squash. Chop into ½ inch (1.5 cm) cubes and toss with a little olive oil. Place on parchment paper on a baking tray. Bake until squash is just tender, about 15 minutes.Heat the olive oil and butter in a large non-stick frying pan over medium-high heat.Add onion and garlic, saute for about 5 minutes then add white wine and saute for another 2 minutes.Add rice and stir for 1 ½ minutes.Add squash and chicken stock, sage, chopped thyme, salt and pepper, stirring occasionally. Transfer to a baking dish. Cook uncovered for 25 minutes until rice is fully cooked.Serve with grated Parmesan Cheese.