Shake the Vinaigrette: In the small jar, combine the extra-virgin olive oil, fresh lemon juice, black pepper, and smoked paprika. Seal the lid tightly and shake vigorously for about 30 seconds until the dressing is emulsified. Set it aside.
Prepare the Salad Foundation: In a large mixing bowl, combine the mixed spring greens, halved grape tomatoes, cucumber half-moons, fresh parsley, and dill.
Dress and Plate the Greens: Pour about two-thirds of the vinaigrette over the salad mixture. Sprinkle with half of the kosher salt (½ teaspoon) and gently toss to coat everything evenly. Arrange the dressed salad on your large serving platter.
Slice the Halloumi: Pat the block of halloumi completely dry with paper towels. Cut it crosswise into uniform ½-inch thick planks. Sprinkle the remaining ½ teaspoon of kosher salt over both sides of the cheese slices.
Heat the Skillet: Place the large cast-iron skillet over high heat. Allow it to preheat for 3–4 minutes, or until you see faint wisps of smoke.
Sear the Halloumi: Carefully arrange the halloumi planks in the hot, dry skillet in a single layer. Sear for 90 seconds to 2 minutes per side. The cheese is ready to flip when it releases easily from the pan and shows deep golden-brown sear marks.
Garnish and Serve: Immediately transfer the hot, seared halloumi onto the bed of dressed greens. Drizzle with the remaining vinaigrette and serve right away while the cheese is warm and soft.