In a small pot bring pomegranate juice to boil, then reduce heat to low and cook until reduced to ⅓ cup.
Place another small pot inside a larger pot filled partially with water to make a double boiler. In the top pot, add butter, sweetened condensed milk and chocolate chips.
Heat the pot over low heat to gently melt the chocolate, stirring constantly to prevent burning.
When the chocolate is completely melted, thick and smooth, stir in the pomegranate concentrate.
Line an 8x8-inch baking dish with foil and lightly grease the foil.
Pour chocolate mixture into the prepared baking dish, gently tapping the dish to smooth out the fudge surface and to remove air bubbles.
Sprinkle the top with chopped pistachios.
Refrigerate fudge for at least 4 hours to set.
Lift the foil containing the fudge out of the pan and cut fudge into 1-inch pieces or desired other size.
Dip your knife into a glass filled with hot water between slices if it is starting to stick to the fudge.
Notes
TO STORE: Store any leftover fudge in an airtight container. It will keep at room temperature for up to two weeks and in the refrigerator for up to one month.TO FREEZE: You can also freeze fudge. Transfer to a resealable bag or freezer safe container and freeze for up to 4 months.