1: First make the bacon butter. Warm a large saucepan over a medium–high heat and cook the bacon trimmings until the bacon starts to crisp and little bits stick to the bottom of the pan. Turn the heat down, add the butter and paprika, and stir everything together. Continue to cook until the butter starts to foam, then pass the mixture through a fine sieve into a container, discarding the bacon, and cool. When cool, seal and place in the fridge until it sets. You can freeze the bacon butter for up to 3 months.
2: To make the fritters, place the sliced onions in a large mixing bowl and season with the flaky sea salt and dried sage. Mix together and leave to stand for 15–20 minutes, until the onions have softened. Wrap the onions in a clean tea towel and squeeze out any excess liquid over a bowl. Reserve the liquid. Put the onions back into a clean bowl and stir in the fresh sage.
3: Stir the curry powder, tapioca flour and gram flour into the drained onion water, to form a paste which is a bit thicker than double cream – you may need to add a little more gram flour. Mix this paste with the onions to make a fritter batter.
4: Heat the oil in a deep fat fryer to 180°C. Gently lower small spoonfuls of the fritter mixture into the oil – they should be about the size of golf balls – and cook until they are golden and crisp. Carefully remove from the fryer and drain on kitchen paper; season. You may need to cook the fritters in batches; make sure you let the oil come back up to temperature between batches. Place in a low oven to keep warm while you finish preparing the rest of the dish.
5: Warm a large, non-stick frying pan over a medium heat and drizzle in a little oil. Dust the pieces of calf’s liver with seasoned flour and shake off any excess. Place them in the pan. When coloured on one side, which will take 2–3 minutes, flip over and add 2 tablespoons of the bacon butter to the pan. Baste the liver. Squeeze in the lime juice and baste again. When cooked – about 4 minutes in total – put the liver on a warm plate to rest for a couple of minutes. Place the pan back on the heat, and add the sherry vinegar and meat stock base to the butter left in the pan. Season and whisk together. Keep warm.
6: To make the spinach, melt the butter in a saucepan over a medium heat, add the spinach, put the lid on and cook for a couple of minutes until wilted. Grate on some nutmeg, season with salt and drain.
7: Cook the bacon rashers over a medium–high heat in a non-stick frying pan until crisp.
8: Place some wilted spinach on a warmed plate and then put a piece of calf’s liver on top. Dress the liver with the bacon butter sauce and then garnish with the sage and onion fritters and crisp bacon rashers. Repeat with the second piece of calf’s liver and serve immediately.