Sure, you can cook beans in a pressure cooker. But, the question is unless the beans are a part of a recipe, why would you want to? It will take about 10-15 minutes for the pressure cooker to reach adequate pressure and then another 15-25 minutes to cook the beans depending on the beans. So, in terms of overall time, you are not really gaining anything.
In any case, depending on the size of the bean, their moisture content....i.e. dried, pre-soaked or canned, and the volume of beans to be cooked, the cooking time can range anywhere from 15-25 minutes. Lentils would take less time - around 15 minutes or less once pressure has been achieved.
As for the farfalle (bowtie pasta) and pappardelle, if they are freshly made and not dried, do not use a pressure cooker. As you know, the cook time in boiling water is only a few minutes. If they are dried, cook time in boiling water is only about 10-12 minutes, perhaps less depending on heat source. So, using a pressure cooker to cook dried pasta could actually take longer once the time it takes to build pressure is factored in.
I hope this helps.
