Tuna Tartare with Avocado and Radish

Name: Tuna Tartare with Avocado and Radish
Ingredients: 2 teaspoons finely grated lime zest or 4 kaffir lime leaves; 2 tablespoons fresh lime juice; 1 tablespoon sugar; 2 tablespoons plus 2 tsp. soy sauce; 2 tablespoons Champagne vinegar or white wine vinegar; 2 tablespoons grated peeled ginger; 10 ounces albacore or bigeye tuna, minced; 2 tablespoon olive oil, divided; 1 teaspoon minced seeded red or green Thai or serrano chile; 1 teaspoon minced shallot; Kosher salt; 1 avocado, halved, pitted; 4 radishes, thinly sliced; Chili oil