Mackerel Tarte Tatin

Name: Mackerel Tarte Tatin
Ingredients: ½ bunch of thyme, leaves only, plus extra; One 4.4-ounce (125 g) tin of mackerel in sunflower oil, drained; One 4.4-ounce (125 g) tin of mackerel in sunflower oil, drained; 3 tablespoons sundried tomatoes from a jar, drained, cut into strips; 6 tablespoons balsamic vinegar; 1 medium white onion; 1 eggplant; 1 sheet of fresh puff pastry