It doesn’t get much better than this!  (c/o chef John Doherty of the Waldorf Astoria)

1 pound sushi grade tuna; cut into 1/4-inch dice
5 tbsp grated coconut; toasted
1 tsp soy sauce
2 tbsp fresh lime juice
1 tsp rice wine vinegar
4 tbsp toasted almond slivers; chopped
4 tbsp currants
1 tbsp vegetable oil
1 tsp fresh ginger; minced
1/2 tsp garlic; minced
1/2 tsp sesame oil
2 ripe avocados
1/8 tsp cayenne pepper
1/4 tsp ground cumin
1/8 tsp paprika
1 tbsp olive oil
Salt and freshly ground black pepper

How to Prepare Coconut Tuna Tartare with Avocado Mousse
In a medium stainless mixing bowl combine the diced tuna, coconut, soy sauce, 1 tablespoon of the lime juice, rice wine vinegar, almonds, currants, vegetable oil, ginger, garlic, and sesame oil.
Toss well and season with salt and pepper.
Cover and refrigerate until ready to serve.
Peel and halve the avocados and remove the pits. Give them a rough chop and place them in a small stainless mixing bowl.
Add the remaining lime juice, cayenne, cumin, paprika, and olive oil.
Mash the seasoned avocado with a sturdy whisk until creamy in texture and season with salt and pepper.
To serve:
Divide the avocado mixture equally into the bottom of 8 martini glasses.
Separate the tuna into eight equal portions and spoon on top of the avocado