Squash in a Skillet

I made this dish yesterday in a cast-iron skillet over a campfire because I needed to find a way to use the vegetables I had in our camping ice chest.  I have never thought of combining squash with peppers, but I had some fresh ones from my daughter's garden.  I expect that zucchini or some other summer squash would be fine as well, if that is what you have.  The blended flavors were surprising and so delicious I decided to share the experiment here. (My husband does not like squash, but he remarked, "Hey, that was pretty good."  That's high praise indeed.)  I'm thinking that some fresh herbs, like basil or tarragon, would make it even better, and I see no reason this wouldn't turn out just as well when cooked on the stove at home!

Ingredients
one medium to large onion, chopped coarsely
one medium to large pepper, chopped coarsely  (I used an orange one.  Red or green would be fine too.)
one or two tomatoes, halved and cut into about 8 pieces
1/2 stick (1/4 cup) butter or more, as needed
3 or 4 potatoes, cut in fourths and then sliced somewhat thin
one large crook neck squash
salt, pepper, garlic

To Do
Saute the onions and potatoes in a large skillet with the butter.  Use more butter, or add some olive oil, as needed.  Add tomatoes and squash.  Sprinkle generously with salt and pepper.  Add about 1/2 tsp. garlic powder or one chopped garlic clove.  Cover and cook, stirring occasionally,  till squash and potatoes are just tender.