Cook all vegetables, except asparagus. Drain and layer all vegetables, including asparagus in a Pyrex pan (13 x 9 x 2 inch). Melt butter. Sprinkle flour into melted butter until you got the consistency of tomato paste. Slowly add milk, stirring constantly until desired thickness is achieved. Texture should be creamy, but not thick. Add shredded cheese and garlic powder, if desired.
Cajun Country -- New Iberia, Louisiana