Boom Bar Burger

1. Preheat oven to 350 F. In food processor, combine both types of mushrooms; pulse until chopped. In medium bowl, combine chopped mushrooms, chopped garlic, chopped ginger, tamari, sugar, ½ teaspoon salt and pepper; mix well.
2. Spread mushroom mixture on a baking tray; gently press down to flatten. Place tray in oven and cook, stirring mixture every 10 minutes, until mushrooms are dark brown, about 20 minutes. Remove from oven and let cool completely.
3. In a large bowl, combine cooked mushroom mixture with ground wild boar. Weigh into 5-ounce portions and gently form into patties.
4. Prepare fried mustard greens: In large Dutch oven, heat grapeseed oil to 350 F. Pat mustard greens dry and tear into large pieces. Working in batches, carefully place greens into hot oil; fry until crispy, about 1 minute. Drain greens on tray lined with paper towels.
5. For Sriracha vinaigrette, combine Sriracha and rice wine vinegar in sealed container; shake vigorously until emulsified. 
6. Cook burgers: Heat a well-oiled cast-iron skillet over medium-high heat. Cook patties until seared on one side, about 3 minutes. Flip and repeat until seared on other side, about 3 minutes. 
7. To serve: spread a thin layer of mayonnaise on bottom of brioche buns. Top with a burger, pickled red onions, and fried mustard greens. Drizzle with vinaigrette and top with other half of bun.

Photo courtesy of Blended Burger Project