Wash lettuce leaves and pat dry. Slice tomato into 4 even slices. Peel and cut 4 thin rings from the red onion. If using avocado, slice half and set aside.

Toast bread (optional)

If you prefer a toasted sandwich, lightly butter one side of each bread slice (about 1/2 tbs per slice) and toast in a skillet over medium heat 1–2 minutes per side until golden. Alternatively, use a toaster and spread butter after toasting.

Warm turkey (optional)

If you want warm turkey, heat a small skillet over medium-low, add 1 tsp olive oil, and warm turkey slices for 1–2 minutes per side until just heated through. Remove from pan and keep warm.

Spread & Seasoning

In a small bowl combine mayonnaise, Dijon mustard, and lemon juice. Stir until smooth. Season with 1/2 tsp salt and 1/4 tsp black pepper; taste and adjust seasoning to preference. This will be the sandwich spread.

Assembly & Finish

Lay out two slices of bread, buttered/toasted side down if toasted. Spread half of the mayo mixture evenly over each slice.

On the bottom slice, arrange half of the turkey (about 4 oz) in an even layer. Top turkey with one slice of cheddar cheese, 2 tomato slices, 1 lettuce leaf, and 3 pickle slices. Add 2 onion rings. Sprinkle a pinch of the remaining salt and pepper (about 1/2 tsp salt total used between both sandwiches and 1/4 tsp pepper).

If using avocado, fan the avocado slices over the vegetables. Place the second slice of bread, spread-side down, on top to close the sandwich.

If you toasted bread but did not warm the sandwich, press the sandwich gently and cut in half on the diagonal. If you prefer the cheese melted, place assembled sandwich in a preheated skillet over low heat, cover, and cook 1–2 minutes per side until cheese softens.

Serve immediately cut into halves with any remaining pickles on the side.