In a 12-inch skillet over medium-high heat, melt the butter until light brown and bubbly. Add the cauliflower, hazelnuts, and sage. Cook for 2 minutes, stirring occasionally. Season with 1 tsp. salt and 1/2 tsp. pepper and continue cooking, stirring occasionally, until the cauliflower is browned and crisp-tender, 6 to 7 minutes more. Remove the pan from the heat. Add the pear slices and parsley. Gently toss to combine and warm the pears. Season to taste with more salt. Serve hot or at room temperature.