cheesy squash + zucchini casserole

Thanks to our very kind neighbor, we have enough squash and zucchini to last us a lifetime.  And green beans, and tomatoes, and peppers too!  I'm not complaining.  It's been wonderful to get all of this *very* fresh produce.  But the squash and zucchini are taking over my kitchen.  So I made a couple of casseroles.  We ate one and froze one for later.  I'm sure you've probably seen squash casserole before, but I did change it up from the usual recipe, and it came out so well I thought I'd share with you. 

3 medium to large squash and/or zucchini
1 sweet onion
3 to 4 T olive oil
3 T fresh basil
2 cups shredded sharp cheddar (I used 1 cup cheddar, 1 cup gruyere)
1/2 to 1 cup sour cream (I used plain greek yogurt)
salt and pepper to taste
topping
1 cup panko
1/2 cup grated parmesan
3 T butter, melted
serves 6

Preheat your oven to 350.  Chop up your squash/zucchini and onion.  Saute both in olive oil until nicely browned.

Chiffonade your basil.  In layman's terms: cut into thin strips.

Add the basil and cheese to your vegetables.  I used gruyere because I had it on hand and I thought it would melt nicely.  But you can use all cheddar, or experiment with other cheese- I love experiments with cheese! 

 Also add the sour cream.  If you've read my blog before, you know by now that I always substitute nonfat greek yogurt for sour cream.  I personally believe it tastes pretty much the same, and helps me feel less ashamed about the immense amount of cheese my cooking contains.  Confession time over.

Mix all of this together well, season with salt and pepper, and transfer into a large casserole dish.  I sprayed the casserole dish with cooking spray first.

Now melt your butter and mix the panko and parmesan cheese in with it.  See?  More cheese.  It's like a disease.  You could use regular bread crumbs or you could be a traditionalist and use Ritz crackers.  Your call.  I had panko, so that's what I used!

 Spread your panko mixture over the top.

 Bake for 20 to 30 minutes, or until the top is browned and the cheese is bubbling.

And enjoy!