Ingredients

• 3 tablespoons extra-virgin olive oil, plus more for sautéing
  
• ¹/₂ medium yellow onion, chopped
  
• 1 cup bread crumbs, fresh or panko
  
• 2 tablespoons roughly chopped mint, plus whole leaves for garnish
  
• 2 garlic cloves, smashed and peeled
  
• ¹/₄ cup grated Asiago (or Parmesan)
  
• 1 large egg
  
• 12 ounces frozen green peas, thawed (about 2 1/2 cups)
  
• Kosher salt
  
• 3 scallions, finely chopped
  
• Freshly ground black pepper
  
• Red pepper flakes
  
• 10 ounces baby bella mushrooms, thickly sliced
  
• Canola oil, for frying
  
• ¹/₂ cup fresh whole-milk ricotta
  
• 4 soft burger buns, preferably potato