Photograph: Kate Whitaker
Preheat the grill on high. Put the peppers on a baking tray and grill them until they're totally black on one side. Turn and grill on the other side until they're charred all over. Transfer the peppers to a bowl and cover with clingfilm to steam.
Once the peppers are cool, scrape away and discard the charred skins and remove the seeds. Avoid washing them as this dilutes their flavour. Slice the peppers into strips.
Add a pinch of sea salt to the garlic paste and put in a bowl with the pepper strips. Marinate for 10 minutes, then add ½ tablespoon of the oil. Tear half the basil leaves and add them to the peppers. Set aside.
Meanwhile, blanch the spinach in boiling water for 20 seconds; drain in a colander. Once the spinach has cooled, lightly squeeze it to remove any excess liquid, then season and add the remaining ½ tablespoon of oil.
To make the olive sauce, blitz the olives in a food processor with the lemon juice, the remaining basil leaves and some seasoning for 30 seconds. Add the olive oil and blitz for a further 5 seconds. Transfer the sauce to a small dish.
Drain the mozzarella, then tear or slice it and arrange on a platter with the dressed spinach, marinated peppers and artichokes. Serve with the olive sauce and grissini.