Preheat outdoor grill to medium high.: As the grill comes up to temperature you will notice the metal heating and a faint smokiness in the air, which primes the meat for a great sear. The right heat ensures a caramelized exterior while keeping the interior juicy. A common mistake is grilling too hot which causes flare ups and an overbrowned outside before the center cooks through, so let the grill stabilize at medium high and brush the grates clean to prevent sticking.
In a large bowl, mix all ingredients together for the burger patties. Divide into 4 even balls and form into patties with a slight depression in the middle for even cooking time. Grill burgers about 5 minutes per side or until done to your liking. Once you flip your patties once, top with a slice of cheese and cover to melt. Toast buns in the last two minutes of cooking, if desired. Remove everything from grill.: The bowl will fill with the scent of BBQ sauce and Worcestershire Sauce , and the grated sweet onion will release moisture that binds the mixture. Mixing just until combined preserves a tender texture, while over mixing compacts the proteins and makes dense patties, so use gentle hands. If the mixture feels too soft, chill briefly before forming patties to help them hold together.
In a small bowl, stir together green chiles and enchilada sauce. Microwave to warm and set aside.: Forming the patties creates a satisfying tactile rhythm, and the center dimple prevents doming as the meat contracts. Press gently to keep them cohesive without smashing out juices. A typical error is making patties too thick which prolongs cooking and risks uneven doneness, so aim for a consistent thickness across all four.
Build burger by topping cheeseburger with lots of green chile sauce and any other desired toppings.: You will hear a steady sizzle as the patties hit the grate and see juices bead on the surface, which signals a perfect sear. Flip once to develop a good crust and avoid poking which releases juices. Overcooking dries out the burger, so check for doneness visually or with a thermometer if you prefer; medium is usually reached near an internal temperature that feels springy to the touch.
Once you flip your patties once, top with a slice of cheese and cover to melt.: The aroma of melting monterey jack cheese under heat is irresistible, and covering traps heat so the cheese softens evenly. Keep the lid closed only briefly to avoid steaming the crust too much. A common slip is placing cheese too early which can cause it to overcook or become oily, so wait until the latter half of grilling to add it.
Toast buns in the last two minutes of cooking, if desired.: Toasting gives the hamburger buns a warm, toasted edge and a faint crunch that resists sogginess from the sauce. Watch closely because buns can go from golden to charred quickly. If you skip toasting, consider lightly grilling them on the cooler side of the grate for a gentler approach.
Remove everything from grill.: The hum of the grill winds down as you transfer patties, buns, and any hot plates to a resting area, and juices will redistribute during a short rest, improving juiciness. Resting also keeps the cheese intact while you assemble. A mistake is skipping rest and assembling immediately which can cause sauces to run and buns to soak through.
In a small bowl, stir together green chiles and enchilada sauce.: Combining the candiced green chiles with the green enchilada sauce releases a fragrant blend of tang and mild heat, and stirring allows the flavors to marry. Warming it makes it easier to spread and lets aromas bloom. If the sauce seems too thick, warm gently and stir; if too thin, let it sit to thicken slightly so it clings to the burger better.
Microwave to warm and set aside.: A brief warming enhances the sauce's aroma and loosens it for spreading, the heat helps meld chile bits into the sauce so every spoonful has flavor. Use short bursts and stir in between to avoid overheating, which can break the sauce. If you prefer, warm on the stovetop in a small pan over low heat for better control.
Build burger by topping cheeseburger with lots of green chile sauce and any other desired toppings.: When you assemble, the visual contrast of glossy green enchilada sauce over melted monterey jack cheese is a clear signal the burger is ready to enjoy, and the first bite should give you a balance of juicy meat, creamy cheese, and tangy sauce. Layer toppings like lettuce , tomatoes , and onions to add crunch and brightness. Avoid piling so high that the burger becomes unwieldy and falls apart mid bite.
