Zucchini Gratin

Today I made my first trip of the year to the farmers market. I wanted to see what was available to use in a side dish for dinner. After seeing the bright green zucchini, I decided to make this easy gratin. It is a yummy Barefoot Contessa recipe that tastes like summer. My mom, nieces, and brother-in-law joined us for dinner and AC declared she wasn't going to eat the "pickle casserole." I assured she and LB that it was only for the grownups. Enjoy!

Zucchini Gratin
3 sourdough bread slices
6 Tbsp. butter
2 onions, chopped
6 zucchini, sliced into circles
2 tsp. salt
1 tsp. pepper
2 Tbsp. flour
1 cup milk, heated in the microwave
3 Tbsp. grated Parmesan cheese
1 Tbsp. butter, cut into small pieces

1. Pulse bread slices in food processor to make breadcrumbs; set aside.
2. Melt butter in a large skillet; add onions, and cook over low heat for 20 minutes. Add zucchini, and cook, covered, for 10 more minutes. Stir in salt and pepper, and cook for 10 more minutes. Stir in flour, and cook 1 minute. Gradually add in hot milk, stirring constantly, until mixture thickens. Pour mixture into a 13- x 9-inch pan lightly coated with cooking spray. Sprinkle fresh breadcrumbs over zucchini mixture; sprinkle with Parmesan cheese. Dot butter pieces along top.
3. Bake at 400° for 20 minutes.