Mel

Shepherds pie! Or a similar incarnation. It’s has whatever ground meat you have on hand or sub impossible crumbles for vegetarians. It covers the basic food groups and is flexible. I usually keep frozen mixed veggies on hand so as long as I have that, some sort of protein and potatoes, the rest is flexible. Got spinach? Throw it in! Leftover broccoli? Good to go!
All that flexibility in one pan and baked so you can clean up while it cooks. And both kids and adults love it. Bonus!