[Fairly] easy-to-add vegetarian protein sources that aren't likely to affect pasta dish flavor?

Maybe this is a big ask, but both people that I live with are fairly newly-vegetarian and we have been struggling to find recipes that contain under 6-7 ingredients and take under 1 hour (1h30min ͟m͟a͟x͟) that also aren't like...sad-tasting?

As such, a lot of the low ingredient count, quick & (potentially) tasty recipes we find aren't very filling, so I'm wondering if anyone could suggest protein sources that would be easy to add in without ruining a dish.

Thanks!!