> lentils give me digestive problems

There are different types of lentils, the most protein heavy is called "toor daal", the one you get in restaurant dishes because it tastes good but is difficult to digest; the most light on the gut is "moog daal" because, compared to toor daal, it has less protein, with just little less "tasty".

> I liked tofu

Also try soya chunks for protein.