Summer Squash Casserole

I found myself in a predicament with too much summer squash hanging around the kitchen from the local CSA. What does one do with all those squashes?! So I thought I would whip up a side dish for dinner that could then be portioned out and taken for lunches to work.

2 tablespoons olive oil
1 large white onion, thinly sliced
3 large cloves fresh garlic, sliced
5 summer squash ('yellow squash') sliced - zucchini or kuda squashes would also be excellent or a mix of all three, roughly 6 cups raw
2 tablespoons balsamic vinegar
2 cups milk
1 tablespoon all-purpose flour
1 tablespoon butter
1 tablespoon fresh thyme
1 teaspoon fresh oregano
1/2 cup panko breadcrumbs
1/4 cup grated cheese (I grated Dubliner)
fresh basil leaves
salt and pepper

1. Preheat oven to 350 degrees.
2. Heat olive oil over med-low, add garlic and onions. Sprinkle with salt and pepper (I grind fresh Himalayan salt and pepper right into the pan). Saute until very soft and fragrant, stirring occasionally.
3. Remove onions and garlic and place in bottom of a glass baking dish
4. Add squash to pan, slightly increase heat, add balsamic and a little more salt and pepper, and let saute until squash starts to soften, about 10 minutes. Then spread over onions in baking dish.
5. Meanwhile, in a separate small saucepan, melt the butter then add the flour and stir until a paste forms. This is your roux to thicken your milk with. Stir the roux in pan until it starts to brown. You are basically toasting the mixture. The darker the brown, the deeper the flavor, but you can definitely burn it too! When the mixture is between the color of a raw walnut and almond it is done. Remove to a plate.
6. Heat milk in same pan (less dish washing!) over medium heat. When milk is warm but not boiling, add thyme, oregano and roux. Raise the temperature of the burner to med-high, whisk the mixture to combine the roux and start the thickening process. As bubbles start to appear on the surface of the milk, it will start to thicken. Cook about another five minutes, whisking constantly, then pour over vegetables in baking dish. NOTE: it might not be enough liquid to fully cover vegetables and that is correct! Sprinkle breadcrumbs over top and grate cheese over breadcrumbs. Bake about 20 minutes or until topping is browned to your liking.
7. Remove from heat and top with ripped fresh basil leaves.

ENJOY!!!