Start by placing 1 lb of ground sirloin and ½ lb of ground chuck into a large bowl. This combination balances lean meat from the sirloin with the fat from the chuck, ensuring juicy burgers without excess grease. Use a fork to gently mix them together, avoiding overworking the meat which can make the burgers tough. The fork method keeps the texture light and prevents the patties from becoming dense during cooking.

Sprinkle kosher salt and black pepper over the meat mixture. Kosher salt stands out because its coarse grains create a beautiful crust on the burger’s exterior while trapping moisture inside for a juicy bite. Stir everything quickly with the fork until just combined, about 10-15 seconds. This light seasoning lets the pure beef flavor shine through, forming the foundation of the ultimate basic burger.

Divide the seasoned meat into portions: four big burgers or six medium ones. Gently shape each into a patty, making the center slightly thinner and more indented than the edges. This prevents puffing during cooking, ensuring even thickness and perfect grilling. Handle minimally to preserve tenderness; overforming compacts the meat and squeezes out juices.

Place the formed patties on a plate, cover loosely, and refrigerate for 30 minutes. Chilling allows the meat proteins to relax after handling, reducing juice loss on the grill. This step is crucial for that signature juiciness. While waiting, preheat your grill pan or outdoor grill over medium-high heat for optimal searing.

Remove patties from the fridge and let them sit at room temperature for about 5-10 minutes. Drizzle both sides lightly with olive oil to prevent sticking. The grill should be hot enough for immediate sizzle, creating a flavorful crust. Pat dry any excess moisture on the surface for better browning.

Place patties on the hot grill. Cook for about 4 minutes per side for medium doneness, flipping only once when the bottom releases easily and juices appear on top. Resist the urge to press down; this squeezes out precious fats and moisture. For well-done, add 1-2 extra minutes per side.

In the last minute of cooking, top each burger with your choice of cheese, like American slices, and cover briefly to melt. Remove from heat and let rest 2-3 minutes. Resting redistributes juices, making every bite succulent. This timing yields burgers that are slightly pink inside, perfectly cooked.

Toast buns on the grill for 1 minute per side. Layer with toppings like arugula, sliced tomatoes, thin red onions, and condiments if desired. Skip watery iceberg lettuce; opt for peppery arugula for freshness that complements the beef. Stack the patty, add the top bun, and serve immediately for peak flavor.