Epis Rubbed Steelhead Trout

Ingredient:

• 1 1/2 cups roughly chopped fresh flat-leaf parsley leaves and stems
• 1 cup roughly chopped white onion (about 1 small onion)
• 1 cup roughly chopped fresh cilantro
• 3/4 cup roughly chopped scallions
• 2/3 cup roughly chopped green bell pepper
• 1/2 cup roughly chopped shallot (1 to 2 shallots)
• 1/4 cup roughly chopped chopped celery
• 1/4 cup extra-virgin olive oil
• 4 medium garlic cloves, peeled
• 2 whole cloves
• 1 1/2 tablespoons white vinegar
• 1 1/2 tablespoons fresh lime juice
• 1 1/2 tablespoons fresh thyme leaves
• 1 medium-size fresh Scotch bonnet chile or habanero chile, stemmed
• 1 1/2 teaspoons kosher salt
• 1 (2-pound) skin-on Steelhead trout or sustainable salmon fillet, scaled and cut crosswise into 3 pieces (see Note)
• 4 teaspoons kosher salt, divided
• 1/2 cup plus 2 tablespoons homemade epis (above) or store-bought epis (such as Creole Me Up), divided
• 1/2 cup extra-virgin olive oil
• 1 tablespoon tomato paste
• 1 large yellow onion, cut into 1/4-inch slices (about 2 1/2 cups)
• 12 garlic cloves, chopped (about 1/4 cup)
• 4 medium-size red bell peppers, cut into 1/4-inch strips
• 1 small fresh habanero chile, finely chopped
• 2 tablespoons white vinegar
• 1 tablespoon avocado oil, plus more for grill basket
• Fresh cilantro, fresh flat-leaf parsley, and edible flowers, for garnish