In a cold skillet, add the shallots and cover them with olive oil.
Heat over medium-high for 3 to 4 minutes, until they are golden and crispy. Do not let them brown too much — remove them as soon as they develop a nice golden color.
Transfer to a paper towel-lined plate and lightly season with salt. Set aside.
In a bowl, whisk together the soy sauce, lemon white balsamic vinegar, lime juice, olive oil, and oregano until well emulsified.
Arrange the salmon and tuna slices on a well-chilled plate.
Scatter the passion fruit seeds over the fish.
Lightly drizzle with the dressing (reserve some for serving), then garnish with a few slices of jalapeño and the crispy shallots.
