Pulse feta cheese in a food processor just enough to get uniformly small crumbles; transfer to a bowl.
Puree red peppers, peperoncini peppers, and cayenne pepper in the food processor until smooth. Mix pepper puree, ricotta cheese, and lemon juice into feta cheese until dip is an even texture and color. Transfer to a sealed container; refrigerate 2 hours to overnight.
This is a good recipe for experimenting. Exchange the peperoncini for a couple of jalapenos and/or add a bit of garlic, etc. Some similar recipes use Greek yogurt instead of the ricotta. The roasted red bell peppers give it the color, which can also be varied.