Preheat the oven to 180C.
Remove the parsley leaves from the stalks and chop the leaves finely. Keep the stalks.
Season the sirloin with salt and pepper.
Top the beans, but do not tail.
Tear or cut the bocconcini into smaller pieces.
Snip the sun-dried tomatoes into strips.
Cut the potatoes into wedges. Do not peel the potatoes.
Boil the potatoes wedges for 10 minutes. Do not cook them longer, as they will go mushy.
Line a baking sheet with baking paper. Place potato wedges on a baking sheet, season with salt and pepper, and drizzle with olive oil. Place in a pre-heated oven for 30 minutes, or until brown and slightly crisp.
Once the potatoes are in the oven, bring a pot of salted water to the boil for the beans.
Blanch the green beans by immersing them in salted, boiling water for 2 minutes.
Take the beans out of the water and drain well.
Lightly toss the hot beans with the sun-dried tomato strips and the oil of the tomatoes. Season with salt and pepper and allow to cool.
Once cooled gently mix through the bocconcini and set aside the salad.
Once the potatoes have been baking for 10 minutes start with the sirloin.
Heat a tablespoon of olive oil in a large pan over medium-high heat.
Add the sirloin and sear until lightly browned on both sides and cooked to the desired level.
Set aside the sirloin and allow it to rest while you prepare the sauce. Add the butter to the pan you used for the steak and let the butter melt before adding the prawns and cooking until just pink on both sides, about 1-2 minutes per side.
Place the prawns in a small bowl and add the lemon juice and the chopped parsley to the bowl.
Into the same pad add the garlic and cook until fragrant.
Add the stock and deglaze the pan by scraping up any brown bits from the bottom with a wooden spoon as the stock sizzles.
Add the cream, Dijon mustard, and Cajun spice, bring to a boil, and let it simmer for a minute.
Add the parmesan cheese and let it melt into the sauce.
Serve the steak topped with the creamy sauce and prawns. Crispy potatoes and crunchy salad on the side.