I've always had issues with lentils but my diet is very Midwest American lol. The only time I've had good lentils is when they're masked as much as possible in heavily spiced curries or similar.

Aren't they already used in a bunch of processed foods as filler?

My mom would make lentil stew with sausage and I always ate the sausage and left the lentils. Was also forced to stay at the table until bed time because I refused to eat them. I need meat with my legumes that is if I am not working because I have a severe carb intolerance so anything from oats, to brown rice to beans and tubers trigger my IBS and make me confused. The only fix was 3 months of straight keto where I felt amazing, was exercising and looked great but... my boyfriend learned how to make pizza thw right way and nothing will ever replace the dough on pizza so once a week I have that, fast the rest and when I eat it's steak or chicken or shrimp or fish with spinach or something. I need to work so I can't just have a bean burrito or a bowl of rice or ill end up fired for spending too much time in the toilet or getting someone killed because I can't think.

Must be nice to have that kind of privilege to eat what you want though!