Preheat Oven: Preheat oven to 180°C fan forced (356°F).
Prepare Potatoes: Cut potatoes with a crinkle cutter into 5mm thick slices.
Season and Bake Potatoes: Toss in 1 tbsp of oil and season with salt. Place on a large oven tray lined with baking paper in a single layer. Bake for 25-30 mins, until golden and crisp.
Sear Steak: Melt tallow in a large frying pan on high heat. Season steak with salt, then sear in pan for 2-3 mins each side until well charred, and cooked medium rare. Set steak aside to rest.
Cook Shallots and Garlic: Add remaining oil and shallots to the frying pan, cook, stirring for 2-3 mins, until softened and starting to brown. Add garlic, stirring for 1 min.
Deglaze and Simmer Sauce: Reduce heat to medium and stir in wine, cook until almost evaporated. Pour in stock, bring to a simmer, stirring. Add butter and cook, stirring until sauce is emulsified.
Serve: Carve steak, serve topped with shallot sauce and crinkle cut chips, garnish with parsley.