Dinner Rut, Advice with Kids

My kids are super frustrating me lately. They are actually pretty good eaters, but the last two new recipes I have made they have all asked me never to make again. We are trying to cut back on meat, so we eat a lot of beans and lentils, which they do like most of the time. I am looking for any suggestions. I could just keep making the same stuff over and over again, but I really want to make something new. I am home for the summer (teacher) and love cooking, so would like to take this time to add some new foods to our regular rotation.

Here is what they saw their favorites are:
Chili, either with beef or without, they don't notice
Texas Pinto beans, as quesadillas (We have this once a week at their request.)
Cheeseburger Pasta
Bacon Chili Beans
Chicken Taco Soup

Ones they eat happily, but "aren't their favorites":
Red Lentil Curry with Kale
Chicken Chili Verde
Sausage and Lentil Stew

What they HAVEN'T LIKED AT ALL recently:
Beef Stew (seriously?)
Thug Kitchen Minestrone
A different bean and veggie soup that I can't remember, but even I thought it was totally boring.

I would appreciate any thoughts, ideas, inspiration. Thanks so much!