Slow cooker beef topside with red wine gravy

Ingredients
1 tbsp black peppercorns
1 tbsp English mustard powder
2 tbsp chopped rosemary
1 tsp celery seeds
15g dried porcini mushrooms
4 tbsp olive or rapeseed oil
1.6kg beef topside, cut into 12 slices
600ml hot beef stock
1 large carrot, peeled and roughly chopped
1 large onion, roughly chopped
2 sticks celery, roughly chopped
2 tbsp tomato purée
200ml red wine
1 tbsp cornflour (optional)

Method
STEP 1
Crush the peppercorns with the mustard, rosemary, celery seeds and a little salt using a pestle and mortar. Blitz the mushrooms to a fine powder in a food processor, then stir them in with 2 tbsp oil and rub all over the beef. Cover and chill for at least 1 hr, but overnight is best.

STEP 2
Heat the slow cooker to high and pour in the stock. Heat 2 tbsp oil in a large pan and brown the beef, then put in the slow cooker skin-side up. Fry the carrot, onion and celery in the same pan over a medium-high heat for about 10 mins. Stir in the tomato purée and wine, scraping the bits off the bottom of the pan, then add this to the slow cooker.

STEP 3
Cook on low for 6 hrs, then strain the liquid into a pan. Keep the meat and veg covered with foil so they stay warm. Bring the liquid to the boil, then simmer until reduced by a third and season. For thicker gravy, mix the cornflour with 2 tbsp water and whisk into the boiling liquid. Serve the beef with the gravy, along with some mash and greens.