To make the horseradish dressing, combine the horseradish cream, olive oil, lemon juice and brown sugar in a bowl. Stir to combine, then season with freshly ground black pepper.
Heat a non-stick frying pan over medium heat and add the bacon. Cook until browned and crispy, then remove with a slotted spoon and drain on paper towel. Add the onion to the pan and cook for 5-8 minutes, or unt