Louisiana Roux

2/3 cup all-purpose flour
1/2 cup vegetable oil
2 cups finely chopped onion
2 cups finely chopped green bell pepper
2 cups finely diced celery

Stir together the flour and oil in a 3-quart microproof casserole. Microwave at HIGH (100%) for 10 to 12 minutes, until flour is deep golden brown, stirring twice. Add the onion, green pepper and celery, tossing to coat.