Place butter in a 2-quart shallow baking dish.
Microwave at HIGH for 55 seconds or until melted, stir in salad seasoning.
Add bread cubes, stir gently to coat.
Microwave at HIGH 4 1/2 to 5 minutes, stirring 2 or 3 times, cool. (Croutons will crisp as they cool.)
Store croutons in an airtight container.