You mentioned some complaining about the food you cooked. I figure:
1. The kids want you to succeed, so if they complain it doesn't mean they are angry with you.
2. I bought a few good cookbooks... - Rachel Ray has a good one for kids (they cook, not you) - Jamie Oliver has 'the food revolution' which gives advice about how to cook & lots of picture based cooking - Mens Health has a Cook This book about cooking food from restaurants at home, again, lots of pictures.
3. When you present the food - be confident in the quality of it. They don't have to like it for it to be a success. I've had amazing dishes that I've done and 3/5 kids LOVED it, and 2 complained. I asked them what they would want in the future, calmly, and then discussed the pros and cons.
BTW - they'll remember their trip, but consider trying to have some good times with them personally while you're there so they remember you and the trip.
