Preheat the oven to 300°F (150°C). Season the beef cheeks with salt and pepper. Place in a roasting pan and cover with beef jus. Roast in the oven for 3-4 hours until tender.

Prepare the Hash

In a skillet, sauté the diced onions and sliced mushrooms over medium heat until softened. Add the slow-roasted beef cheeks (shredded) and halved fingerling potatoes. Cook until the potatoes are tender and everything is heated through.

Eggs and Sauce Preparation

Poach the Eggs

Bring a pot of water to a gentle simmer. Crack the eggs into a small bowl and gently slide them into the simmering water. Cook for about 4 minutes for soft poached eggs, then remove with a slotted spoon.

Make the Hollandaise Sauce

In a heatproof bowl, whisk the egg yolks and lemon juice together. Place over a pot of simmering water and whisk until thickened. Slowly drizzle in the melted butter while whisking continuously. Season with salt and cayenne pepper.

Salad Preparation

Prepare the Salad

In a bowl, combine arugula and diced tomatoes. Drizzle with olive oil and balsamic vinegar, then season with salt and pepper to taste.

Assembly

Plate the Dish

On a plate, serve a generous portion of the beef hash. Top with a poached egg and drizzle with hollandaise sauce. Serve with a side of the arugula and tomato salad.