Use a mandoline or a sharp knife to finely shave the fennel into thin slices. Slice the purple snow peas in half lengthways. Toss the fennel and snow peas in a mixing bowl.
Pop the ricotta in a separate bowl. Grate in the zest from the lemon. Finely chop a quarter of the mint leaves. Finely chop the chilli and the garlic clove. Add them all to the ricotta. Beat everything together with a wooden spoon till well incorporated.
Squeeze the lemon juice into a separate bowl. Whisk in 1 tbsp olive oil and a good pinch of salt and pepper to make a dressing. Pick the remaining mint leaves off their stems. Finely slice any large leaves.
Layer the fennel, purple snow peas and mint leaves on each plate, adding generous spoonfuls of the flavoured ricotta to each layer. Spoon over the lemon dressing and serve.