Whisk yeast, sugar, salt, beer, vinegar, coriander, and lime juice in a large bowl until smooth.
Add flour, whisk until combined, and let the batter rest for one hour.
Preheat a deep fat fryer to 190°C.
Dip crabs in batter and fry for 3-4 minutes until golden and crisp.
Drain crabs on kitchen paper and season with salt.
Boil garlic in white wine for a few minutes then drain.
Process egg yolks, vinegar, mustard, and salt while gradually adding olive oil to emulsify.
Add saffron, garlic, and lemon juice to the aioli and blend.
Toss watercress, mint, and pea shoots in a bowl.
Heat vegetable oil in a wok and fry the chillies for two minutes.
Serve crabs topped with fried chillies alongside the salad and aioli.