Have the peas thawed. Grease a springform pan (20 cm Ø) and dust with flour. Wrap the outside of the tin with aluminium foil. Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer).
Peel and finely dice the shallots. Wash the mint and shake or dab dry. Chop the leaves, except for a few for garnishing. Grate pecorino finely.
Beat the eggs with the whisk of the mixer. Stir in the ricotta and sour cream. Stir in the shallots, mint, pecorino and lime zest. Mash half the peas with the hand blender, also stir in.
Season vigorously with salt, pepper and nutmeg. Fold in remaining peas.
Spread the mixture into the mould. Bake in a hot oven for about 50 minutes. Then take it out and let it rest on a cake rack for about 10 minutes.
In the meantime, wash the chives, shake them dry and cut them into coarse rolls. Remove the tart from the tin. Sprinkle with chives and mint leaves. Serve with sour cream.