Preheat the oven to 180C degrees.
Chop the courgette and aubergine into bite-size chunks. Cut the onion into 6 wedges. Chop the garlic. Scatter them all into a big roasting dish, tuck the tomatoes in between. Sprinkle with the oregano, season with salt and pepper, then drizzle with the oil.
Bake in the oven for approx. 30 minutes until the vegetables are golden and tender.
Drain the beans and add to the veggies, together with the parsley. Drizzle with the lemon juice, season to your liking and combine gently.