Plant directly in the fungus or germinate in nursery and move into this fungus when the plant has taken root. Then you save space in your large growing boxes.
Do as the pros, grow in foam mushrooms. This medium for hydroponic cultivation is by far the most common in professional cultivations. The medium is only there to keep the seed in place and give it moisture at the beginning of the cultivation. When the plant has its roots, it sticks to the pot. With foam sponges you avoid soil diseases, mold and other nuisances.