Fry the bacon in a medium-sized non-stick pan over medium-high heat until crispy. Remove from the pan and place on a paper towel to drain, preferably in a warm place. (In the oven on a low setting is perfect.) Keep the bacon fat in the pan; turn the heat up to high.
Season the halloumi cheese with a pinch each of salt and pepper, then place it in the pan with the bacon fat and brown on all sides, 30 to 60 seconds per side. Once the cheese is browned, remove it from the pan and place it with the bacon to stay warm.
While still on the heat, add the spinach to the pan, season with a pinch each of salt and pepper and leave to wilt for about 1 minute. Remove from the pan and place with the rest of the components.
To serve, spread the pesto in the centre of a serving plate, then add the spinach, avocado, halloumi and bacon. Top with the fried egg. If desired, finish with a pinch each of Maldon salt and pepper.