In a small bowl, mix the drained tuna, sour cream, mayonnaise, grainy dijon mustard, chopped gherkins, a splash of the gherkin brine, and chopped fresh dill until thoroughly incorporated. Set aside.

Preheat a non-stick frying pan or cast iron skillet over medium heat.

Once warm, drizzle the olive oil into the pan and let warm for a few seconds.

Place two slices of the bread into the pan, using your hands to carefully rub the bottom of each slice into the oil in the pan.

Arrange the shredded cheese onto the topside of each slice of bread, dividing it evenly between the two.

Divide the dill pickle tuna salad onto the top of each slice. Toast sandwiches until golden brown on the bottom, for about 3-5 minutes.  Remove from the pan and set aside.

If needed, add another small drizzle of olive oil to the pan.  Toast the remaining two slices of bread to your liking and remove from the pan.

Arrange the toasted bread on top of each prepared sandwich, sprinkle additional fresh dill over the top of each sandwich, and serve. Enjoy!