Pub-style steak sarnie with beer onions recipe | Sainsbury`s Magazine

Ingredients

• 1 x 225g ribeye steak (or sirloin or rump), trimmed of fat
• 1-1 1⁄2 tbsp made English mustard, to taste
• 75g light mayonnaise
• 1 tsp olive oil
• about 250g stonebaked white baguette, halved horizontally
• 20g watercress
• chips, to serve
• 2 large onions, thinly sliced
• 150ml chilled beer (such as a pale ale)
• 1 tbsp olive oil
• 10g butter
• 1 tbsp honey
• vegetable oil, to fry
• 30g cornflour
• 2 tsp English mustard powder
• 1⁄2 tsp fine sea salt