This makes a substantial amount of salsa so you will probably end up with more than you can pile on your oatcakes. Enjoy the rest on its own.
Tip the beans, lemon juice, ricotta, 50g feta and the garlic into a bowl and blitz with a hand blender or in a food processor to make a paste. Stir in the remaining feta and spoon the mixture into four small pots.
To make the salsa, stir all the ingredients together with the mint (if using) and divide into four more pots, topping with a lemon wedge. These will keep, chilled in an airtight container, for two-three days. To eat, spread the oatcakes with the bean mixture, squeeze the lemon wedges over the salads and pile generously onto the oatcakes.