Place the eggplant into a large bowl. Sprinkle over the salt and drizzle over the olive oil. Toss the eggplant making sure they are coated in the oil.
Heat a griddle pan over medium-high heat, place the eggplant halves onto the griddle making sure the grill lines run across the width of the eggplant (so you get mini grill lines running across the white part of the eggplant).
Turn the heat to medium and leave them cooking without moving them for 2 minutes.
Then turn them over and cook on the other side. Turn them occasionally and cook for 5-6 minutes until tender.
When the eggplant are cooked, switch off the heat and take them off the grill, place on a serving plate.
Spoon a tablespoon of the marinara over each eggplant half.
Decant the rest of the marinara into a small bowl so guests can help themselves to more.
Sprinkle over some finely chopped basil. Serve immediately.