Wash the chicory leaves, cut them into small pieces and put them in a bowl. Wash the apple, cut it into quarters, remove the core and cut each piece into four slices; then chop them into pieces and put them in the bowl as well. Clean the artichokes, then slice them very thinly lengthwise and add them to the bowl with the other ingredients. Season everything with an emulsion prepared by mixing the oil and the juice of half a lemon together with a fork. Add the ricotta, crumbled roughly with your hands, season with salt and freshly ground pepper, and mix all the ingredients together delicately, taking care not to crumble the ricotta up too much.