Mince the beef, pork and fat and form into 165g patties on baking paper, 140mm in diameter and thinner in the middle. Freeze till use

In a non stick fry pan fry the patty on one side for 6 minutes. This will create a crust. Pat dry excess moisture.
Flip and fry 1 minute. Sprinkle with Salt. Put crusted side up on a tray. Keep warm in a 70deg oven

Using an egg ring just melt 20g of the parmesan over low heat in a non stick pan. Remove the pan from the heat. Remove the egg ring and using a spoon thin out the disc making larger. Make 4

Thinly slice the tomatoes. Sprinkle with salt. Dry on paper towels
Slice the mushrooms and fry in butter 3 minutes. Remove, pat with paper towels to remove excess butter. Toss in a small bowl with truffle oil.
Cut the bacon into 75mm pieces. Just fry the bacon 90 seconds.
Shred the lettuce and dry.
Slice the onions thinly.
Shave some truffle.

Toast the buns till brown. 1 minute

The build::
First, on each of the top and bottom buns spread some mayonnaise and squirt over some tomato sauce.

From the top down::
Top bun with condiments
Cheese
Bacon
Truffle shavings
Mushrooms with truffle oil
Patty
Tomatoes
Lettuce
Onions
Bottom Bun with condiments

Serve with onion rings. 

300g Chuck Steak
300g Pork Butt
150g Pork Fat
4 Tip Top Hamburger Buns
200g Shitake Mushrooms
4 Fatty Bacon Rashers
80g Parmesan grated
2 leaves Iceberg Lettuce
1 Tomato (very ripe)
1 Onion sliced into pieces
Truffle shavings
Truffle oil
Mayonnaise
Tomato Sauce
Salt

.

This is about as decadent as a burger can be. Really good with so much flavour. At a quality deli you will occassionally find fresh truffles. Spend $50 on a fresh knob and be amazed at how good it is. The more overpowering the smell the better it is. Use pretty much straight away. Store in a small plastic container surrounded by rice. Then use the rice in a rissotto.

Quality Truffle oil is a great product. I use it regularly. Particulaly on my scrambled eggs or stir through a milanese rice at the end of cooking. It actually is a totally fake product. It may have a small bit of truffle in the bottle for decoration but in reality it contains no truffle. Its a chemical compoud that just happens to taste and smell exactly like truffle. Diluted in quality olive oil. Nevertheless, a great ingredient that has a place in my pantry.

This is another dish that works because it is loaded with so much umami. Natural MSG.