Turn on the oven to preheat to 180 degrees. Grease an ovenproof dish with butter.
In a large skillet, heat 1 tablespoon butter and 1 tablespoon olive oil. Pour the onion and sage into the pan. Cover the pan with a lid and cook over low heat and cook for 10-15 minutes, until caramelized.
Steam the pumpkin until soft, about 10 minutes. Then transfer to a bowl, add garlic, 3/4 teaspoon of salt, mix well.
Sprinkle the onion in a frying pan with salt and pepper, stir and cook for another 20-25 minutes (it should be caramelized). Mix the caramelized onions with the pumpkin and place in a prepared ovenproof dish, and top with hot cream.
Mix the bread crumbs with the melted butter and sprinkle over the vegetables in the mold. Put in a preheated oven and bake until brown, about 40 minutes. Then the baked pumpkin can be served.