1In 10-inch skillet, heat 1 inch water to boiling. Stir in salt. Add cauliflower and return to boiling. Boil uncovered 3 minutes or until almost tender. Drain cauliflower in colander and immediately rinse under cold water to stop cooking. Set cauliflower aside.
2In same skillet, melt 3 tablespoons of the butter over medium heat. Stir mustard into butter and add bread crumbs. Cook 8 to 10 minutes, stirring frequently, until crumbs are golden brown. Remove crumbs to plate.
3In same skillet, melt remaining tablespoon butter and the oil over medium-high heat. Stir in cauliflower and cook about 5 minutes, stirring occasionally, until lightly browned and cooked through. Sprinkle crumbs over top.