I feel your pain! Cooking is my least favourite domestic activity.
It can be frustrating but I just keep offering the healthy choices and leaving it at that.
One thing that surprised me. My own dd is very choosy in what she will eat. Classic picky eater. Went out with a friend's family to a sushi restaurant. Loved it! Miso soup and sushi are her new favourites. This is a kid that if asked, will tell you that pizza and tacos are her favourite. Who knew! She is really resistant to trying stuff with us but did it no problem under peer pressure, ha ha.
Favourites here:
quesadillas (made with chickpeas - Looney spoons cook book)
chicken parm
veggie chili with toast fingers (or buns if I've had time to make them)
soups (all kinds, esp beef and barley)
turkey nuggets
sweet and sour meatballs
Everyone's favourite veggie is broccoli. I hated it as a child but this group will eat it every day, lol. And butternut squash. I will sneak pureed veggies into meals.
Snacks I always do raw veggies and fruits, along with other choices but they are always served. With or without dips. Something we did once was made a fruit salsa, toasted some tortilla wraps, and then used them to dip in the salsa. Delish!
I like to check out some blogs, too, for ideas. Super healthy kids. 100 days of real food. I've asked my older ones for ideas and have 1 day/week of kids' choice (within reason). Usually it's quesadillas or pancakes or scrambled eggs.