Preheat the oven to 425 degrees F.
Heat the olive oil In a large, oven safe skillet over medium heat. When the oil shimmers, add the shallots and cook until fragrant, about 2-3 minutes. Add the mushrooms, thyme, dill, crushed red pepper, and season with salt and pepper. Cook undisturbed for 5 minutes or until golden. Add the butter and wild rice, cook 2-3 minutes, until the rice is golden and toasted. Pour in 4 cups of water. Bring to a boil, cover and reduce heat to low. Cook, covered for 40-45 minutes.
Once the rice is cooked, stir in the broccoli, spinach, and ½ cup of each cheese. Season with salt and pepper. Scatter the remaining cheese over top the casserole.
Transfer to the oven and bake 20-25 minutes, until the cheese is melted and just beginning to brown. Serve warm with additional thyme.
