Grilled Swordfish Sliders

Ingredients

• 1 tablespoon kosher salt, plus more to taste
• extra-virgin olive oil, to taste
• 1 cup apple-cider vinegar
• freshly ground black pepper, to taste
• 1 red onion, sliced thinly
• 1 tablespoon grapeseed oil
• 1 pound swordfish steaks
• 10 slider buns, split
• 1 pint cherry tomatoes
• 1 tablespoon honey