Thomasina Miers’s Fish Tacos

Method

1. First make the guacamole. Check the heat of the chilli by nibbling the tip furthest from the stem. Most generic supermarket chillies are quite mild but, if it is hot, remove the seeds, or leave it out entirely if your guests are totally heat-averse.
2. Put one-quarter of the onion, the garlic, the chilli and salt in a pestle and mortar and mash to a rough paste. Cut open the avocados, remove the stones and scoop the flesh into a large bowl, adding the onion, garlic and chilli paste. Roughly mash the flesh with a fork, adding half the lime juice as you go. When you have a rough guacamole, stir in the remaining lime juice and onion with the coriander and tomato. Season with plenty of black pepper. If it doesn't taste delicious at this stage, think whether it might need seasoning with more salt, lime juice or coriander. When you are happy put it in a bowl on the table.
3. Season the fish with salt and pepper. Mix the mayonnaise and crème fraîche together and put in a bowl on the table.
4. Heat the olive oil in a frying pan over a medium heat and fry the fish for a few minutes each side until cooked through. Season with a squeeze of lime juice.
5. Heat the tortillas in a microwave or a dry frying pan and put them on the table in a basket, wrapped in a tea towel to keep them warm. Place the grated cheese and salsa in separate bowls and add to the table with bowls of lettuce. Invite your guests to fill their tortillas with whatever they want, roll them up and tuck in.