Instructions

• In a large skillet over medium–high heat on the stove, warm the oil. Add the onion and cook for 3 minutes, stirring occasionally, until lightly browned. Reduce the heat to medium–low and cook another 5 minutes, stirring occasionally, or until well softened. Add the wine, thyme, ½ teaspoon of salt and ¼ teaspoon of pepper and bring to a simmer. Reduce the heat, simmer until the liquid reduces to a glaze and the onions are very tender, about 10 minutes, stirring often. Remove from the heat and cover to keep warm.
• Prepare the grill for direct cooking over medium–high heat (200ºC to 260ºC). 
• In a medium bowl mix the ground chuck, paprika, ½ teaspoon of salt and ½ teaspoon of pepper. Gently form four patties of equal size, each about 2 centimetres thick. With your thumb or the back of a spoon, make a shallow indentation about 2.5 centimetres wide in the centre of each patty to prevent them from doming as they cook. Refrigerate the patties until ready to grill.
• Grill the patties over direct medium–high heat, with the lid closed, until cooked to medium doneness, 9 to 11 minutes, turning once. During the last 30 seconds to 1 minute of grilling time, place a slice of cheese on each patty to melt and toast the buns, cut-side down, over direct heat. 
• Build each burger on a bun with a patty, caramelized onions and baby greens. Serve right away.