Okay, you don't have to grill this. The oven works fine. I never did. Be careful cutting the squash. You can just stick the skewer through the squash to hold it back on or buy more squash than you need.
This is my favorite way to eat zucchini.
Leaving onion out of this casserole is okay.
Let me know, please, if you make either one of these and how your family commented.