Remove most of the parsley stalks and finely chop the leaves. Line a large baking tray.
Add the chickpea flour to a sauce pan along with the pepper, salt and parsley. Then whisk in the water until there are no clumps left.
Bring the mixture to a boil while whisking it constantly to avoid it from sticking and burning on the bottom of the pan. Lower the temperature to a simmer, switch to a spatula and keep stirring until the mixture begins to thicken (1-2 min). Continue cooking for around 5 minutes until it has thickened into a thick batter that pulls away from the sides and doesn’t level out anymore. Turn off the heat.
Pour the mixture onto the lined baking tray and spread it out with a spatula until you have a thin layer. Let it cool entirely (30 min).
For the gremolata, twist off the leafy bit of the parsley, pick the mint leaves and add both to a small bowl of a food processor. Peel the garlic, trim and deseed the chilli. Roughly chop both and add them to the processor as well along with the salt. Then pulse until finely chopped. Grate in the zest of the lemon, followed by 3 tbsp of lemon juice and the olive oil and stir to mix through.
Heat the oil to 170°C. While the oil is heating up, cut the panelle into roughly 7 cm x 7 cm squares. Then fry 4-5 squares at a time for around 4 minutes until they are golden brown. Place a few paper towels on a cooling rack. Once the panelle are cooked, let them drain off any excess oil on the paper towels. Continue with the rest until all the squares are fried. Then serve in the baps with a sprinkle of sea salt, an extra squeeze of lemon juice and, optionally, the gremolata.