Why is my pistachio cream too runny?

Runny pistachio cream usually means too much oil — either from over-processing (nut oils release more the longer you blend) or from adding too much liquid. Fix it by chilling the mixture: refrigerate for 30 minutes, which firms up the oils. If it's still too loose, add more ground pistachios or a tablespoon of coconut cream that will firm on cooling. Commercial pistachio paste tends to be thicker than homemade — if your paste is thin, use less tahini to compensate.