Heat a grill pan over medium-high heat or heat a grill to medium heat.
Brush the halloumi slices with 1 tablespoon of olive oil, coating both sides of the cheese.
Place the halloumi on the grill pan or grill and cook on each side for 2 to 3 minutes or until grill lines form and the cheese is melting.
Toss the sliced cucumbers, halved tomatoes, greens, and mint together. Spread them across a large, low bowl or large plate.
Mix the remaining olive oil, lemon juice, sea salt, and pepper together. Drizzle across the salad.
When the halloumi is done cooking, add it to the salad and serve immediately.