In a mixing bowl, combine shallot, garlic, and jalapeños. Season with salt. Let sit 10 minutes at room temperature.
Add Sherry Vinegar from Spain. Let sit 5 minutes at room temperature.
Add remaining ingredients. Mix to combine and set aside.
Arrange sliced fish on a serving plate.
Pour desired amount Tomato-Sherry Vinaigrette over fish.
Garnish with sesame seeds and grated tomato.
Season with salt.
