If you boil cumin or other seeds, do the volatile oils get released into the sauce? As above, if you use fennel, cumin or other seeds whole, will the oils get released into the pot liquid or must one ground the seed then add for the oils to come out?
Fennel and cumin will release their flavors if cooked long enough in a sauce. I usually fry them in oil before adding other ingredients as I like the result, but that's not a required step. If you have a short cooking time use powdered. You can also crush the seeds in a mortar and pestle to speed up flavor release.