Step 1

In small bowl, add porcini mushrooms and enough hot water to cover. Let stand until mushrooms soften, about 15 minutes. Using slotted spoon, transfer mushrooms to cutting board and chop.

Step 2

Off heat, coat grill rack or large grill pan with nonstick spray. Preheat gas grill or grill pan to medium-high, prepare medium-high fire in charcoal grill.

Step 3

Meanwhile, arrange 4 bacon slices in single layer between paper towels. Microwave on High until bacon is partially cooked but still flexible, about 30 seconds. Drain bacon on paper towels. Repeat with remaining 4 bacon slices. Let cool.

Step 4

In large bowl, mix beef, cremini and porcini mushrooms, onion, and 1⁄2 tsp salt and shape into 4 (31⁄2-inch) patties. Season with 1⁄4 tsp each salt and black pepper. Arrange 2 bacon strips crisscross on each patty, tucking ends underneath.

Step 5

Arrange patties, bacon-side down, on grill and cook for 6 minutes. Turn patties over and cook until bacon is crisp and instant-read thermometer inserted horizontally into patties registers 160°F, about 6 minutes more. Sprinkle a scant 1⁄4 cup cheese over each patty. Close lid and continue to cook until melted, about 30 seconds.

Step 6

Sprinkle tomato slices with remaining 1⁄4 tsp salt. Build burgers with roll bottom, 1 patty with bacon and cheese, 1 tomato slice, 1 lettuce leaf, sliced onion (if using), and roll top.

Step 7

Serving size: 1 burger