Preheat the oven to 180°C (356°F).
Halve the eggplants horizontally to make 4 halves and scoop out the flesh, leaving about a 1-inch shell all around; sprinkle the shells with 1 tablespoon salt and set them aside to draw out moisture.
Rinse the scooped eggplant shells to remove excess salt, then pat them dry with paper towels.
Chop the reserved eggplant flesh finely and transfer to a mixing bowl with the beef mince, chopped onion, minced garlic, diced tomato, 2 tbsp parsley, 2 tbsp basil, 2 tbsp breadcrumbs, and 1 tbsp vegetable stock powder. Mix until combined.
Line the base of a baking dish with foil and pour half of the 14 oz can of tomato soup or pasta sauce into the dish.
Place the eggplant shells scoop-side up in the baking dish and evenly fill each shell with the beef mixture.
Pour the remaining tomato soup/sauce over the stuffed eggplants, then sprinkle the tops with 1 tablespoon breadcrumbs.
Cover the dish with foil and bake in the preheated oven for 45 minutes.
Remove the foil and switch the oven to grill/broil; cook for an additional 5–10 minutes until the tops are golden and slightly crisp.
Spoon any sauce from the dish over the eggplants and sprinkle with the remaining 1 tbsp chopped parsley and 1 tbsp chopped basil before serving.