Grilled Swordfish with Salsa Verde

Name: Grilled Swordfish with Salsa Verde
Ingredients: Grated zest of 3 lemons, plus 2 halved lemons; 10 cloves garlic, smashed; 2 cups olive oil, plus more for the grill; 1/4 cup fresh thyme, chopped; 1 tablespoon Ottoman spice or Aleppo pepper; 8 1-inch-thick swordfish fillets (8 to 10 ounces each); 1/2 small red onion, sliced 1/4 inch thick; 1 small jalapeno pepper; 1 tablespoon sherry vinegar; 2 tablespoons chopped fresh parsley; 2 tablespoons chopped fresh cilantro; 1 tablespoon chopped fresh mint; Juice of 1/2 lime; Kosher salt; 2 avocados, pitted and quartered (skin on); 1 bunch watercress, trimmed; Flaky sea salt