To make the béchamel sauce:
- In a pot, slowly bring the milk to a slight simmer.
- In the meantime, cook the butter and flour (roux) over low heat for 15 minutes.
- In a separate pot, bring the cream to a boil.
- Gradually whisk the milk into the roux to prevent lumps from forming.
- Bring the mixture to a boil to cook and thicken the flour.
- Add the cream and whisk together. Transfer the sauce to a container and cover the surface with cling film to prevent a skin from forming.
To make the truffle Mac & Cheese Mixture:
- Cook the pasta in plenty of salted boiling water until al dente.
- Drain the pasta and spread it on trays to cool in the fridge.
- In a large bowl, mix the cooled pasta with the ½ recipe of béchamel sauce, Dijon mustard, truffle paste, truffle oil, parmesan cheese and salt until well combined. Check for seasoning and adjust as needed.
To make the bacon jam:
- Pre-heat a large frypan over medium-high heat and cook the bacon for about 10 minutes, stirring frequently until cooked but still chewy.
- Using a slotted spoon, remove the bacon from the pan and set it aside.
- Reserve one tablespoon of the bacon drippings and discard the rest.
- Add the onions to the pan and cook for about 8-10 minutes.
- Reduce the heat to low, add the brown sugar, and stir.
- Continue cooking until the onions have caramelized, about 10 minutes.
- Increase the heat to medium and add the coffee, ½ cup of water, and the cooked bacon.
- Cook, stirring every five minutes, until the onions are thick and jam-like, about 30 minutes.
- Remove from heat and stir in the balsamic vinegar. Season to taste.
To make the truffle mayonnaise:
- Whisk together the Port Mahon Mayonnaise, tartufata, black truffle oil, porcini mushroom powder, water and salt until well combined.
- Store in an airtight container until ready to use.
ASSEMBLY:
- Butter one side of each piece of bread.
- Place one slice of bread, buttered side down, on a clean working surface or plate.
- Spread an even layer of truffle mayonnaise on one slice of bread.
- Cover the other slice with bacon jam.
- Top both slices of bread with cheddar cheese, then spoon the truffle mac & cheese mixture on top.
- Sprinkle with more cheddar and place another slice of bread, buttered side up, on top.
- Heat a large non-stick pan over medium heat.
- Place the sandwich in the pan and cook until the bread is golden and the cheese