2. Add the butter and work with your fingertips until the mixture forms coarse crumbs. Cover and refrigerate.
2. In a large skillet over medium heat, heat the olive oil. Add the butter and when it melts, cook the onion, coriander, and bay leaf, stirring occasionally, for 3 minutes or until softened.
3. Add the tomatoes and cook for 3 more minutes. Add the butternut squash, sage, salt, and pepper. Turn down the heat. Cover and cook for 30 minutes or until the vegetables soften.
5. Discard the bay leaf from the squash mixture. Sprinkle with parsley and Parmesan; stir gently. Transfer the vegetables to the baking dish. Spoon the crumble mixture on top.
6. Bake for 30 to 35 minutes or until the top is golden.