Grilled Beef Sirloin with Pommes Dauphinoise, Pea Purée and Crispy Garlic Mushrooms
By M&S Food
Published on 08 September 2025
A steak night showstopper, brought together with bold British flavours and smart shortcuts. Creamy potato dauphinoise, sweet pea purée and golden mushrooms complete this standout plate from Elliott Grover as seen on Cooking with the Stars.
Time and servings
1 hrTotal time
2Servings
15 minsPrep time
45 minsCooking time
Ingredients
- 450g M&S Collection Potato Dauphinoise
- 200g M&S Crispy Breaded Mushrooms
- 1 tbsp butter
- 300g frozen peas
- 100ml chicken stock
- 2 British sirloin steaks
- 1 tsp M&S Steak Seasoning
- 1 tbsp vegetable oil
- 4 salad onions, trimmed
- 1 baby gem lettuce, trimmed and halved
- 1 tbsp olive oil
Method
Step 1
Preheat the oven to 200°C/180°C fan/gas 6. Place the potato dauphinoise in the oven and bake for 45 mins. Add the crispy breaded mushrooms for the final 10-12 mins of cooking time or cook the mushrooms in an airfryer set to 200°C for 8min.Step 2
Meanwhile, make the pea purée. Melt the butter in a pan over a medium heat. Add the frozen peas and chicken stock, season with salt and pepper, and simmer for 5 mins. Transfer to a blender and blend until smooth. Keep warm until ready to serve.Step 3
Press the steak seasoning all over the steaks. Heat the vegetable oil in a large pan over a high heat. Sear the steaks on each side until medium-rare, or until cooked to your liking (around 2 -3 mins per side for medium rare). Hold the steaks on their fatty edges to render and crisp the fat. Transfer to a plate, cover and rest for 5-10 mins.Step 4
While the steak rests, use the same pan. Add the salad onions and cook over a low heat for 2-3 mins until just tender. Slice the baby gem lettuce into thin wedges, add to the pan and toss for 1 min in the steak juices until just wilted.Step 5
Plate the rested steaks with the potato dauphinoise, pea purée, crispy breaded mushrooms, and the wilted salad onions and gem lettuce. Drizzle the lettuce with olive oil before serving.