Boy that is a tough bunch of parameters...the most digestible legumes are probably lentils and mung beans. Lentils come in all sorts of colors and can be cooked lots of ways. I'm not sure what kind of grain products you can tolerate, but I like millet and wild rice. I use millet like I would rice, it takes about the same amount of time to cook, is a "white" whole grain, and tastes good. If you can tolerate wheat, sietan is a good meat substitute, I think it is mainly gluten, so for many people that would be an issue. If you can eat potatoes, you can probably handle carrots and hard squash. One sort of weird veggie that I like that you can probably eat is watermelon radishes, roasted. They taste wonderful, but are a little hard to find. I usually buy them at the farmer's market. If they grow here, the ought to grow where you are. I don't grow my own radishes because they hate me; they either bolt in 10 days or are so hot you feel like you've had a horseradish cleanse.
Can you handle tree nuts? They are a very good source of protein in a little package. How about eggs in baked goods? Have greens, a yummy Keith okay veg, baked lentils and corn bread for a meal.