Tricky! My DS isn't a consistent eater but I've found changing the finger foods I'm giving him seems to keep him a bit interested. Cobs of corn, slices of rockmelon, pieces of cooked chicken, steak, toast, plain bread sticks (enjoys crunching those), grilled cheese on toast, halved cherry tomatoes, thick slices of cucumber, steamed broccoli, carrot and pumpkin... as well as spooning baby yoghurts and trying the organic range of baby foods. Plus I just keep giving him bits off my plate to try. He's still getting what he needs from breastfeeding and weight's good but I also worry about what happens when he starts to wean.
I don't know if any of that helps at all. I struggle with patience. It takes so long sometimes for DS to eat anything substantial. We haven't had the gagging thing really to deal with but I did use those mesh food holders for grapes and banana and steamed vegetables right at the start because I was worried about DS choking. Have you tried one of those? Good luck!! Hope someone comes up with some good ideas for you!