Combine the salt, lemon zest, paprika, black pepper and cumin in a mixing bowl, and then rub all sides of the ahi tuna generously with the mixture. Place the tuna in a shallow pan, cover with plastic wrap and let marinate in the refrigerator 30 minutes.
Heat the olive oil, fennel, parsley, shallots, thyme and rosemary in a large saucepot over low heat until the oil reaches 160 degrees F. Gently place the tuna into the oil and cook to medium-rare, 6 to 8 minutes. Carefully transfer the tuna to a paper-towel-lined baking sheet using a fish spatula, and let rest in a warm area 2 to 3 minutes.
Slice each ahi steak across the grain into 5 slices using a sharp knife, and then arrange in an overlapping semicircle in the center of 4 plates. Place approximately 1/4 cup of the Fennel Tarragon Salad on top of the tuna on each plate to form a "crown". Garnish each plate with 2 each caper berries, fennel fronds and olives.
Drizzle the Green Tomatillo Verde Sauce around the perimeter and serve immediately.
Combine the fennel and roasted bell peppers in a mixing bowl. Mix together the lemon juice, tarragon, vinegar, shallots, Dijon, lemon zest, salt and white pepper in another bowl. Add the olive oil in a slow steady stream, whisking constantly until the dressing has thickened. Pour the dressing over the fennel and peppers, tossing lightly to coat. Cover the bowl with plastic wrap and refrigerate to allow the flavors to marry, 30 minutes. Just before serving, gently mix in the pine nuts.
Place the tomatillos in a pot of boiling water and simmer until soft. Transfer to a food processor with the chicken stock, cilantro, onions, garlic, lime juice, salt, black pepper, green onions and jalapeno and puree.