Drain the beans in a sieve, rinse with cold water and drain well. Clean and wash the spring onions, divide the white part into small rings and the rest into 2 cm long pieces. Wash tomatoes, pat dry and cut in half. Rinse the parsley, shake dry, finely chop the leaves. Peel the garlic, cut into slices. Squeeze the lemon.
Heat oil in a pan. Sauté the spring onions and garlic in it. Add tomatoes and beans, fry with them. Season with lemon juice, sugar, salt and cayenne pepper. Chop the tuna with a fork and fold into the beans. Pour in the broth and heat slowly.