Sliders au jus

Combine ground beef, ½ of the onion and Worcestershire sauce in large bowl; shape into 8 2.5-inch (6.25-cm) patties. Heat olive oil in small skillet over medium heat and cook remaining onions, stirring occasionally, 5 minutes or until tender and starting to brown. Stir in garlic and rosemary and cook 2 minutes. Stir in Knorr® Au Jus Gravy Mix and water. Bring to a boil, whisking constantly. Reduce heat to low and simmer 1 minute. Grill patties, turning once, until done, about 4 minutes. Arrange lettuce, tomato and burger on bottom half of bun. Spoon Au Jus on burger and top with other half of bun. Serve with remaining au jus.