Mix oil, oregano, paprika and garlic in a small bowl.
Place salmon on a large plate. Rub 1 teaspoon of the oil mixture over the top of fillets. Cover and set aside.
Combine eggplant, zucchini, capsicum and onion in a large roasting pan. Drizzle with remaining oil mixture and toss well to lightly coat. Spread vegetables in an even layer. Bake vegetables in a preheated 220 °C oven (fan-forced) for 20 minutes.
Remove pan from oven. Turn vegetables. Sit salmon fillets on top. Scatter over pine nuts. Return to same oven. Bake for a further 10 minutes or until vegetables are tender and salmon is cooked to your liking.
Sprinkle with mint leaves. Serve with tzatziki, pita bread and lemon wedges.