Remove the leaves from the parsley. Finely chop the parsley leaves and garlic (by hand or in a small stand mixer).

Squeeze the juice from the lemon over the top and stir to combine. Season with salt and pepper.

Place an ovenproof skillet over medium-high heat.

Season the halibut generously with salt and pepper.

Add the oil to the hot pan and then add the halibut, skin-side up. Cook just long enough to sear the fish.

Turn the fish so the skin side is down, sprinkle the cherry tomatoes around the fish, and transfer to the oven. Bake until the fish is cooked through and the tomatoes are beginning to burst, 20 to 30 minutes (this will vary depending on the thickness of the fish, but 30 minutes is for a filet that is approximately two inches thick at its thickest part).

Remove from the oven and spread the gremolata over the halibut. Serve immediately.

Preheat oven to 300 degrees Fahrenheit.