This is a really nice dip. I've made it using both baby spinach leaves as well as the variation Alyce suggests using a 50/50 combination of baby spinach leaves and rocket leaves. I don't normally like rocket on it's own, it's a bit too peppery for my tastes, but in this dip, both worked out beautifully.
I find the lemon/vinegar taste to be quite strong when it is first made, but after being in the fridge for a few hours/or overnight the sharpness if that disappears and it's a really tasty chunky dip!
Will make regularly!