Place a rack in the center of your oven and preheat the oven to 450 degrees F.
Let the salmon rest at room temperature for 10 minutes. With paper towels, pat it dry on both sides.
In a small mixing bowl or liquid measuring cup, whisk together the honey, hot water, lemon juice, garlic, smoked paprika, ¼ teaspoon salt, and cayenne pepper. Keep near the stove.
Heat an ovenproof skillet (cast iron is ideal) just large enough to hold the salmon comfortably over medium high—you don't want the salmon to overlap, but you also don't want there to be too much extra room around the salmon or the sauce may burn.
Sprinkle the salmon with ½ teaspoon salt and ¼ teaspoon black pepper (wait to season the fish until just before adding it to the pan).
Once the skillet is hot, add the olive oil. Swirl to coat the pan, then add the salmon, skin-side up/flesh side down. When lowering the fish into the pan, move it in a direction away from you so that you aren’t splattered with oil. Sprinkle the skin side of the fish with a generous pinch of additional salt.
Cook the salmon for 4 minutes without disturbing it, until it is browned and releases easily from the pan. With a thin spatula (a fish spatula is perfect), carefully turn over each fillet. Turn off the heat.
Pour the honey mixture over the salmon fillets. With a spoon, baste the top of the fish with the sauce for 1 minute.
Transfer the skillet to the oven. Bake until the salmon flakes easily with a fork, about 4 to 5 more minutes for 1-inch fillets; if your salmon is thicker or thinner, you will need to adjust the cooking time accordingly. Salmon is done when it reaches 145 degrees F on an instant read thermometer and flakes easily with a fork. Do not overcook or the salmon will be dry (once I get close to 145 degrees F, I remove the salmon to a plate then cover it and let it rest a few minutes so the carryover cooking finishes the job).
Sprinkle the salmon with parsley or green onion and squeeze additional lemon over the top if you like. Enjoy hot with more pan sauce spooned over the top.
If your honey starts to get very dark, don't panic! It is the sugar caramelizing and your fish should not taste burned. If this happens, it may be that your skillet is too large (so the honey cooks more quickly) or too hot. Take it as a learning for next time and enjoy your salmon.
TO STORE: Refrigerate leftover salmon in an airtight storage container for up to 2 days.
TO REHEAT: Honey garlic salmon can be very gently reheated in a skillet over medium-low heat.