To make the stuffing, heat 1 tablespoon of the olive oil in a large frying pan. Add the shallots, squid tentacles and finely chopped fennel and cook for about 10 minutes, or until the squid and fennel are tender.
Stir in the fennel seeds, chilli flakes and garlic and cook for another 2 minutes.
Add the anchovies, remove from the heat and stir vigorously until the anchovies dissolve into the sauce.
Blanch the chard in a saucepan of boiling salted water. Drain, refresh and squeeze out any excess liquid. Finely chop the chard and add to the frying pan. Season the fennel mixture with salt and pepper and stir through the almonds and breadcrumbs. Once cool, transfer to a food processor and pulse a few times to bring the mixture together. Transfer to a piping bag.
To make the tomato sauce, heat the olive oil in a large saucepan, add the garlic and cook for a few minutes without browning. Add the tomatoes and cook for about 15 minutes over a medium heat (or slightly longer if using tinned). Season and stir in the basil.
Stuff each squid body with a little of the stuffing mixture from the piping bag, closing each squid with cocktail sticks.
Heat the remaining olive oil in a large frying pan over a high heat and add the squid, a few at a time, to sear. When browned, transfer to the tomato sauce pan.
When all squid are seared, cook gently in the tomato sauce for about 10 minutes. Transfer to a serving dish, drizzle with olive oil, garnish with basil and sprinkle over the pecorino. Serve immediately.