Tuna Avocado Ceviche with Salsa Macha

Name: Tuna-Avocado Ceviche with Salsa Macha
Ingredients: 1 1/2 pounds fresh ahi or albacore tuna, cut into 1/2-inch cubes; 1/2 cup Salsa Macha , plus more to taste; 1 teaspoon fine sea salt, plus more to taste; 1 cup diced English cucumber; 1 cup diced red onion; 1 medium-size firm avocado, cut into 1/2-inch cubes; 2 tablespoons fresh Key lime juice (from about 4 Key limes), plus more to taste; 1/2 cup fresh cilantro leaves; Tostadas, for serving