Garudapurana 1.187.13

1.187.13

bhṛṅgarājasya vai mūlaṃ puṣyarkṣe tu samāhṛtam /
vidhāya tasya cūrṇaṃ vai sasauvīrañca bhakṣayetaṃ //

Having gathered the root of bhṛṅgarāja under the Puṣya asterism / and made a powder of it, one should eat it with fermented barley-water;