Heat your oven to 180°C/Fan 160°C/Gas 4. Trim the aubergine and courgette. Chop them both into chunks around 2 cm across. Pop in an ovenproof dish.
Halve the baby plum tomatoes. Peel and grate or crush the garlic. Add them both to the veg with 1 tsp of the fennel seeds.
Drizzle 1 tbsp olive oil over the veg. Season with salt and freshly ground pepper. Stir the veg so it's well coated in oil and seasoning. Pop in the oven for 25 mins till the veg is tender and starting to char a little.
Take the veg out of the oven. Measure out 1 tbsp of the black olives. Roughly chop them. Stir them into the veg.
Pop the rainbow trout fillets on top of the veg, skin side down. Season with a little salt and pepper.
Pop the dish back in the oven for 10 mins till the trout is dark pink and cooked through.
Divide the rocket between two plates. Top with the roast veg and the trout fillets. Serve straight away.