Tuna Ceviche in Radicchio Cups

Name: Tuna Ceviche in Radicchio Cups
Ingredients: 1 pound sushi-grade tuna, cut in 1/4-inch cubes; 2/3 cup quartered cherry tomatoes; 1/4 cup thinly sliced red onion; 2 tablespoons finely diced jalapeño; 2 tablespoons finely chopped cilantro, plus more for garnish (optional); 1 teaspoon grated garlic; 2 tablespoons extra-virgin olive oil; 1 teaspoon lime zest; 2 1/2 tablespoons fresh lime juice; 2 tablespoons fresh lemon juice; 1/2 cup 1/4-inch-diced avocado; 12 radicchio cups; Fine sea salt and freshly cracked black pepper