- Heat your oven to 400º F.
- Toss the butternut squash onto a large sheet pan along with the onion and garlic cloves. Drizzle with olive oil, season with salt and pepper, and toss well to combine. Roast for 25 to 30 minutes or until tender and caramelized, stirring once halfway through cooking.
- Lightly grease a three to the three-and-a-half-litre casserole dish with non-stick cooking spray.
- In a large bowl, beat together the eggs then whisk in the milk and/or cream, mustard, smoked paprika, and nutmeg and season with one teaspoon of salt and half a teaspoon of pepper. Squeeze the roasted garlic from its skins, mash with a fork into a paste, and whisk into the egg mixture.
- Cut the bread into one-inch cubes and scatter half into the prepared casserole dish followed by half of the kale, half the herbs, and half of the roasted squash and onions. Repeat these layers with the remaining bread, kale, herbs, and roasted veg then pour over the egg mixture. Scatter the grated cheese overtop and cover with a lightly greased piece of aluminum foil. Set aside for at least 30 minutes.
- Heat your oven to 350º F. Bake the covered strata for 25 minutes then carefully remove the foil and continue to bake for another 25 minutes or until puffed, golden brown, and the center is set. Allow it to sit for 10 minutes before serving.
TIP: If looking to get ahead, assemble the strata the night before. Cover with lightly greased aluminum foil as instructed and store in the fridge for up to 12 hours. To bake, place the covered strata into your cold oven and heat it to 350º F. When the oven is up to temperature, bake as directed above.