Remove the halloumi from its packaging and pat it thoroughly with paper towels to eliminate excess moisture. Using a sharp knife, cut the cheese into slices roughly 1.25 cm thick.
Warm the olive oil in a non-stick or cast-iron skillet over medium heat until shimmering.
Carefully place the halloumi slices into the hot skillet in a single layer. Let them sear undisturbed for about 2 to 3 minutes on each side, or until they develop a deep golden crust and turn crisp.
Transfer the cooked slices to a serving plate. While still hot, drizzle generously with fresh lemon juice and serve at once.