Preheat the oven to 200°C/fan 180°C /Gas 6. Make the slaw by combining the red and white cabbage, onion and carrot in a bowl. Add the olive oil and lemon juice, along with some seasoning, then mix well with your hands to soften the cabbage. Set aside while you prepare the salmon.
Place the fish fillets, skin-side down, on a baking tray with the lemon wedges and add seasoning. Bake in the oven for 12-15 mins, until just cooked through.
Divide the salmon fillets, slaw and lemon wedges between serving plates, then scatter the chopped dill over the top before serving.