Start by marinating the tuna. Drain the oil from the tin of tuna into a bowl, then stir in two tablespoons of olive oil, the harissa, grated tomato, garlic and a half-teaspoon of salt.
Add the tuna to the mix, keeping the chunks as large as possible, then gently toss to combine and set aside.
Mix the borlotti and black-eye beans in a large bowl with all the remaining ingredients apart from the ricotta, then stir in half a teaspoon of salt and plenty of ground black pepper.
When you’re ready to serve, drain the ricotta, put it in a bowl and beat with a fork until very smooth and spoonable.
Spread the ricotta evenly on a platter, then top with the beans. Spoon the tuna chunks and their marinade over the beans and finish with a sprinkle of salt.
