1) Position a rack about 15cm from the grill and preheat. Cook the bacon in a large (30cm) ovenproof nonstick skillet over medium-high heat until crispy, about 8 minutes. Transfer to a paper towel-lined plate and crumble the bacon when cool.
2) Add the potato, 1/2 teaspoon of salt, paprika, and basil and cook, stirring occasionally, until the potato is brown and tender, about 8 to 10 minutes.
3) Meanwhile, whisk the eggs and milk with the remaining 1 teaspoon salt and black pepper to taste.
4) Add the shrimp and bacon into the skillet and stir until the prawns are pink, about 1 minute. Remove the skillet from the heat and pour the eggs over the potatoes and prawns. Stir the egg, potatoes and prawns mixture just until the eggs begin to set and the potatoes and prawns are evenly distributed in the skillet. Scatter the cheese over the eggs and top with the red pepper.
5) Grill the tortilla in the skillet until the eggs are set and the cheese begins to brown, about 2 to 3 minutes. Serve the tortilla from the skillet. Alternatively, use a rubber spatula to loosen the eggs from the side of the skillet and invert onto a plate, invert the tortilla again, onto a serving platter or invert and slide tortilla onto a cutting board. Slice into wedges and serve garnished with cheese and parsley.