Mix all the dressing ingredients in a large bowl, give the mixture a good stir, and set aside for now.
Heat some oil in a small pan.
Add the onions and cook for a few minutes before adding the brown sugar.
Once the sugar dissolves, which shouldn’t take more than a few minutes, pour in the balsamic vinegar.
Cook for a few minutes until the onions are juicy and tender. Set aside for now.
Brush both sides of the Beyond Meat patties with oil and place them on a flat griddle pan.
Cook the patties for four minutes per side. Remove from the heat.
Place a slice of cheddar cheese on top of the patties to soften them.
Generously butter the pretzel buns and toast until golden brown.
Place a leaf of iceberg lettuce on the bottom, followed by the burger and the cheese slice.
Top with tomato slices, the pickles, and lastly, the onion slices.
Pour the dressing mixture over the top bun before serving.