Drain canned tuna thoroughly — press firmly in a Colander or squeeze in a paper towel to remove as much liquid as possible. Excess moisture prevents browning. Mix drained tuna with mayo, lemon juice, salt, pepper, and any mix-ins like celery, pickles, or red onion. If making a sandwich melt, butter one side of each bread slice and set aside. Slice your cheese and have everything ready before the Skillet heats up — cook time moves fast.

Preheat a Skillet over medium heat for about 1 minute. Medium heat is key — too high burns the bread before the cheese melts, too low gives soggy results. For a tuna melt sandwich: Assemble with tuna on the unbuttered side of the bread, add tomato slices if using, then layer on two slices of cheese. Top with the second slice buttered side up. Place in the skillet cheese side down. Cook undisturbed 3 to 4 minutes until deep golden brown on the bottom. Flip and cook another 3 to 4 minutes until the second side is golden and cheese is fully melted. Total cook time is 4 to 8 minutes depending on pan, heat, and bread thickness. For loose tuna without bread: Add tuna mixture directly to the preheated skillet over medium heat. Stir and cook about 5 minutes until heated through and moisture has cooked off, stirring occasionally to prevent sticking.

Reduce heat to medium. Add the remaining 2 tablespoons of Unsalted Butter to the same Skillet. Once melted, add the Minced Garlic and sauté for about 1 minute until fragrant, stirring constantly so it doesn't burn. Pour in the Chicken Broth (or White Wine) and Lemon Juice, then add the Lemon zest and Italian Seasoning. Stir and let the sauce simmer for 2–3 minutes until slightly reduced.

Return the Salmon Fillets to the Skillet and spoon the lemon Garlic Butter sauce over each fillet. Let everything warm together for 1 minute. Garnish with Fresh Parsley and Lemon slices, and serve immediately.