Char each side of the eggplant on the burner grate to blacken the skins (this should take about 15 minutes).
Wrap each charred eggplant in foil.
Bake the foil-wrapped eggplants for 15 minutes on a sheet tray in the oven
Cool the eggplants under refrigeration until they are completely cool.
Add the dates to a stainless steel bowl and cover with 24 oz. of boiling water.
Cover the bowl with film and allow the dates to hydrate under refrigeration until they are completely cool.
Reserve 4 oz. of the date soaking liquid.
Peel the skins off the hydrated dates and discard. Ensure there aren’t any pit fragments in each date by pressing the date with your fingers gently.
Transfer the dates and reserved soaking liquid to a Vitamix blender or equivalent.
Open the foil-wrapped eggplants and pour the cooking liquid into a stainless steel bowl lined with a strainer.
Split each eggplant in half and discard the stem by working over a parchment-covered cutting board and wearing gloves. Also remove any large sections of the bitter seed pods. Keep the flesh, jus and charred skins, then transfer to the blender with the dates. The charred skins will give the jam its unique black color.
Purée the mixture until smooth, adding the sweet soy to the blender.
Season the purée with salt and pepper as desired.
Adjust the consistency, as desired, by cooking the jam in a sauce pot, stirring frequently.
Transfer the jam to a half-size hotel pan and place under refrigeration to cool.
Place the jam in desired containers with fitted lids, squeeze bottles or pastry bags for service.