OP, you have to know that kodiak pancakes and veggie pizza are not going to be a universal crowd pleaser with kids.

We hold playdates after lunch so we don't have this problem. But grilled cheese or cheese pizza is probably safe for most kids. A few fruits so that they can choose one that they like.

DC is 6, we've only recently begun doing playdates again so kids are usually playing too hard to want to break for a real lunch we tend to offer an assortment of healthy-ish snacky things rather than a sit-down meal; sometimes food assembly becomes an activity in and of itself (e.g., making smoothies out of a choice of frozen fruits). Vegetables with hummus, granola bars and yogurt cups, PB&Js (you could do sunbutter instead) and DIY flatbread pizzas have all gone over well.

Pizza with carrot sticks, broccoli and celery sticks on the side. PB&J sandwiches with apple slices or berries. Mac & cheese. Stuff like that.

Play dates are not the time to push healthy eating on friends, so I would throw that out the window. Plain cheese pizza (not whole wheat, no veggies), boxed Kraft or Annie’s mac and cheese, and frozen regular chicken nuggets are my go to options that almost all kids like. With fruit and veggies on the side - like slices apples and cucumbers, strawberries or sugar snap peas. Dips are also popular - mashed avocado with chips, hummus and veggies etc. on the side, but not all kids like them so I would serve them along side a meal.

I generally feed my kids more like you do on a regular basis, but playdates are special occasions where I want both kids to have fun and eat so they aren’t cranky. Occasional ‘junk’ food isn’t going to ruin your kids eating habits. If I am eating lunch too, I’ll always offer the kids what I’m having in case they want to try something else. If I have the same kids over repeatedly, I’ll learn what kind of things they like and how open they are to trying new things.

Plain pasta with butter, jarred red sauce (Rao's), shredded parmesan or mozzarella available as toppings.

Simple cheese quesadillas.

Both with applesauce or cut fruit plus cut up veggies and ranch.

If we are doing dinner, sometimes I will do "make your own pizza" - I make dough into heart shapes (I have girls) and let the kids dress their own pizzas with sauce, cheese, various cut veggies...

Blueberry muffins, mini bagels, cut up strawberries, applesauce

I serve my own kids food that’s take it or leave it and I feel the same about play date guests LOL. And I do often do play dates in between meal times and then only offer snacks.

But I will ask if there are any allergies etc. but I have fed kids hot dogs, hamburgers, chicken nuggets, Mac n cheese, and we would do PB & J if no allergies. I’ve done lunch meat - Turkey & cheese.

Most kids do only like plain cheese pizza LOL.

I don't worry about how good for you the main dish is and always serve a fruit and a vegetable. I usually offer a couple choices from the following: mac and cheese, soup, chili, veggie/chix burger, pizza, dumplings, pasta (plain or with sauce), quesadilla.

What's wrong with you OP? Heat up a frozen pizza and call it a day. Serve some fruit on the side.

It's great that your kids will eat those things, but mine wouldn't at that age. They would eat healthy foods, but in a particular way that it was offered at home. They wouldn't want veggies on a pizza or a healthier version of a pancake with Greek yogurt. You gotta think about how kids typically eat.

I would say peanut butter and jelly but that's out.
Chicken nuggets
Mac and cheese
Hot dogs
Cheese pizza
Pasta with the option of sauce or without

Annie’s Mac and cheese, strawberries, slice cucumbers works well

Grilled cheese, chicken noodle soup, pb&j assuming no allergies. All with a side of carrots and apples or grapes.

Plain pasta with tomato sauce and shredded mozzarella available to be added.

Cold cuts, on bread or plain, with potato chips or popcorn or pretzels.

Grilled chicken breast with ketchup or barbecue sauce available, and same sides as cold cuts.

Melt cheese on tortilla chips, serve with salsa for dipping and avocado if they want.

I need some simple, healthy ideas for playdate lunches I could make for ages 4-7 that won't get rejected.

I've had several bad experiences of making food for DD and her friends and the friends just refusing the food.
one time i made Kodiak cakes pancakes with greek yogurt and maple syrup and the friends (twins) thought it was "weird" and wouldn't eat it.
another time i made a frozen flatbread pizza with veggies and that was rejected b/c of the veggies. having to tell the parents they wouldn't eat any lunch wasn't a good feeling!
we don't do nut butters - allergies, typically we don't do fast food either.