Preheat the oven to 200°C.
Chop the sweet potato into 2 cm chunks (no need to peel!).
Place on a baking tray.
Drizzle with a splash of oil and season with salt and pepper. Rub the seasonings into the sweet potato.
Roast on the top shelf of the oven 20 - 25 minutes until soft and browned at the edges, turning half way through cooking.
Remove any stalks from the cherry tomatoes in half lengthwise, Place in a bowl.
Season with salt. This will draw the juices out of the tomatoes and create a delicious base for the dressing.
Grate in the zest of half the lime and add a good glug of olive oil.
Roughly chop the coriander and add half to the tomatoes.
Stir the tomatoes, cover and keep to one side.
Slice the avocado in half lengthwise. Twist apart and remove the stone. Slip a spoon around the edge of the flesh of the avocado to pop it out of the skin.
To make the Crema, chop half the avocado into small chunks and place in a bowl. Using a fork, mash the avocado to a smooth paste and add a squeeze of lime juice and a pinch of salt. Stir in the sour cream and mix until smooth.
Chop the other half of the avocado into 2 cm chunks and toss it into the tomatoes.
In a large bowl, mix the flour with the Cajun blackening spice and a good pinch of salt.
Add the fish to the bowl and coat in the flour.
Heat a splash of oil in a frying pan over medium-high heat.
Add the cod to the pan skin side down and cook for 4 minutes.
Turn the cod over and cook for 5 minutes, until golden. The fish is cooked when the centre is opaque.
When the potatoes and fish are both cooked, you can get ready to plate everything up.
Divide the rocket between two plates, covering the whole base of the plate.
Nestle the sweet potato chunks in the rocket.
Lay the cod in the centre.
Spoon the tomatoes and juices around and over the fish.
Drizzle with the avocado crema and sprinkle with the remaining coriander.
Serve and enjoy!