Preheat the griddle pan to medium-high.
Coat the steak in oil and rub with the paprika, garlic, onion and some salt and pepper. Dress the scallions with a little oil as well, and season with salt and pepper.
Grill the steak about 12 minutes, turning once. While the meat rests, grill the scallions until marked.
Dress the cress with the lemon juice and 1 tablespoon of olive oil, and then season with salt and pepper.
Slice the steak against the grain, 1/4-inch thick. Fan the steak on a plate and top with the grilled scallions, cress and the crumbled blue cheese.