Ingredients

• For the porcini powder, mushroom broth, roasted veggies, and mushroom-infused oil:
• 1 ¹/₂ ounces dried wild mushrooms, preferably porcini, divided
  
• 1 quart chicken or vegetable broth
  
• 8 ounces (each) button and cremini mushrooms
  
• 6 ounces portobello mushrooms
  
• 3 ounces shiitake or mixed wild mushrooms
  
• 2 small-medium leeks, white and light-green parts only, well-washed
  
• 1 large sweet onion, peeled
  
• 2 or 3 celery stalks, with leaves if possible
  
• 2 or 3 carrots, peeled, with tops if possible
  
• 1 fennel bulb, cored, outer layer removed if tough
  
• 4 garlic cloves, peeled, any green shoots removed
  
• ¹/₂ teaspoon (each) dried thyme, marjoram, ground fennel seed, and ground celery seed
  
• salt and freshly ground black pepper to taste
  
• 1 ¹/₂ cups olive oil, plus extra for roasting
  
• parmigiano-reggiano heel (2 x 2 or so)
  

• For the finished ragu:
• ¹/₄ cup mushroom-infused olive oil (see above; or substitute plain olive oil), plus extra for drizzling
  
• 4 ounces pancetta, small dice
  
• 1 pound ground bison or buffalo meat
  
• 1 tablespoon tomato paste
  
• 1 tablespoon porcini or other wild mushroom powder (see above)
  
• ¹/₄ cup Italian parsley, finely chopped
  
• reserved celery leaves and carrot tops, if using
  
• 1 cup dry red wine
  
• 15 ounces can roasted tomatoes (diced or crushed)
  
• chopped fresh tarragon, for garnish
  
• salt and freshly ground black pepper to taste
  
• freshly grated parmigiano reggiano