Place cheese into Thermomix bowl and grate for 2 sec/speed 6. Set aside.
Place walnuts, peppercorns and salt into Thermomix bowl and mill for 6 sec/speed 7.
Add umami paste, beef mince, sauce and grated cheese to Thermomix bowl and combine for 10 sec/Reverse + speed 7 with the aid of the spatula.
Form into 6-8 equal burger patties, place onto baking paper and refrigerate until ready to cook.
Clean bowl before making the dressing by placing all ingredients except EVOO into Thermomix bowl and mixing for 10 sec/speed 6. Add oil and stir through for 4 sec/speed 6. Drizzle over rocket leaves and set aside.
To assemble burgers; Char grill buns and patties to taste. Cook bacon. Spread mayonnaise on bottom half of bun, add cooked burger patty, top with slice of tomato, dressed rocket leaves and a slice of bacon. Drizzle with additional dressing if desired.