How to Make It
Light a grill and preheat the oven to 350°. Brush the tuna steaks with 2 tablespoons of the olive oil and season with salt and pepper. Grill the tuna over moderately high heat until lightly browned but still pink in the center, about 3 minutes per side. Transfer the tuna to a large platter and let cool.
In a food processor, pulse the bread cubes until coarsely chopped. Transfer the crumbs to a baking sheet, toss with 1 tablespoon of the oil and spread evenly. Toast for about 15 minutes, or until lightly golden and dry; let cool.
In a small bowl, mix the minced shallots with the red wine vinegar and 1/2 teaspoon of salt and let stand for 15 minutes. Drain the shallots and transfer them to a large bowl. Add the currants, mint, parsley, tarragon and capers, balsamic vinegar and the remaining 1/2 cup of olive oil. Season with salt and pepper. Add the toasted bread crumbs and toss well. Spoon the salsa over the grilled tuna steaks and serve right away.