Hand mix your patty ingredients together in a large mixing bowl until consistent. Roll into 4x pool-ball sized balls and let rest.
Eggplant Mac Sauce
Add chopped eggplant to a colander and cover with salt. Let sit for 5 minutes or so, until water droplets form on the outside of the flesh.
Rinse, dry, and add to a large Lodge cast iron skillet with enough oil to cover the bottom. After 2 minutes on a medium-high heat, add garlic and sauté until the eggplant starts to get mushy.
You will notice the eggplant soaks up the oil, so you may need to add small amounts as it cooks. Season with salt and pepper.
Add the sugar. Once the sugar has dissolved, add the vinegar.
When the mixture has turned to a thick, mushy paste, take off the heat. Add mayonnaise, tomato sauce, and the wholegrain mustard and mix.