In a bowl, combine the softened butter, miso paste, chopped kimchi (if using), and chopped basil until smooth; refrigerate if not using immediately.
Soak the cedar plank in water for at least 30 minutes, preferably 2–4 hours, then preheat the grill to medium (about 350°F).
Whisk together 2 tablespoons of the honey, 1/4 cup soy sauce, grated ginger, and minced garlic to make the marinade.
Place the salmon in a zip-top bag or shallow dish and pour the marinade over it; refrigerate for 30 minutes.
Remove the salmon from the marinade and place the whole fillet on the soaked cedar plank, ensuring no edges overhang; season with salt and pepper.
Place the cedar plank directly on the preheated grill, close the lid, and cook about 12–15 minutes until the salmon is uniformly pink in the center and cooked through.
Use a large spatula to transfer the plank with salmon to a flat surface and let it rest briefly.
In a small bowl, mix the remaining 1/4 cup honey, 1 tablespoon soy sauce, sesame oil, and toasted sesame seeds to make the honey glaze.
Thread cherry tomatoes onto skewers, drizzle with olive oil, and season with salt and pepper.
Place the tomato skewers on the hot grill and cook about 5 minutes, turning every 2–3 minutes, until charred and softened.
Brush the cooked salmon with the honey glaze, reserving any extra for serving; top with dollops of the kimchi-miso butter and sprinkle with fresh basil and sesame seeds.