Halve the avocado, remove the core, remove the peel and cut everything into small pieces. Put everything (100 g avocado pieces, 125 g ricotta, ½ teaspoon lemon zest, 1 tablespoon lemon juice, 1 tablespoon olive oil and 2 big pinches of coarse sea salt from the mill) into a slim, tall vessel and puree with a hand blender.