Open Beef Sammies with Caramelised Onions and Béarnaise Sauce

Steps

1. Preheat oven to 220°C. Line and oven tray with baking paper. Preheat BBQ grill to high (if using). Prepare your ingredients. Toss roasties on prepared tray with a drizzle of oil and season. Bake for about 25 minutes, until golden and tender. Turn once during cooking.
2. Heat a drizzle of oil in a small pot on medium heat. Cook onion, stirring, for about 5 minutes, until starting to colour. Add vinegar and sugar, stir, reduce heat to low-medium and simmer for about 10 minutes, until thick. Stir often to avoid burning. If onion sticks, add a splash of water.
3. Pat beef dry and season. Heat a drizzle of oil in a large fry-pan on medium-high heat. Cook beef for 2-3 minutes each side for medium (depending on thickness), or until cooked to your liking. Set aside, covered, to rest for 5 minutes. Slice thinly.
4. When roasties have 10 minutes cook time remaining, push roasties to one side of the tray and place slices of sourdough on other side of tray.
5. Return tray to oven to bake for final 8 minutes of cook time (for roasties), until sourdough is lightly toasted. Thinly slice tomato and cucumber and add to a large bowl with mesclun, oil and vinegar. Toss to combine and season.
6. To serve, top a piece of sourdough with caramelised onions, slices of beef and a good drizzle of Béarnaise sauce. Divide open beef sammies, salad and roasties between plates.