In a 6- to 8-inch frying pan over medium heat, stir pine nuts often until golden, 5 to 10 minutes.
In a bowl, mix mashed beans, basil, mayonnaise, parmesan, lemon juice, capers, currants, green onion, and garlic until well blended. Add salt and pepper to taste.
Arrange tomato slices, overlapping, on a platter. Spoon bean mixture down the center of tomatoes. Sprinkle with pine nuts.