Roasted Leeks and Mushrooms with Cannellini Beans

I follow a number of foraging accounts on Instagram and many of them were talking a lot this spring about the importance of foraging for wild onions. Wild onions, or onion grass are an invasive species to Pennsylvania and the North East and bolt out of the ground each spring as the soil temperatures warm. Accounts were suggesting that if you want to forage them, you should just pull up the entire bulb. Yes, you’ll be depleting stock in the local area, but there will most likely be another rogue cluster a few steps away should you ever return for more. 

Now you’re thinking, what on earth does this have to do with leeks and beans. Well, let me tell you. While I found the notion of foraging for my own food and solving an ecological disturbance in one motion, I have tried to use wild onions before, and they’re just not for me. I did find myself one day in the grocery store stumbling on a pack of beautiful looking leeks. I’m note sure of the general allium family was on my brain, but I said to myself, “I can make something with these.” When I brought them home, I realized I didn’t look up any special way to use them and would have to get creative. My wife had just made some sourdough and I knew we had some Parmesan and white wine in the fridge. If I was going to make it a meal I knew we’d need protein so that’s where the cremini mushrooms and beans came in to play. 

The roasted leeks and mushrooms and depth of flavor and structure to the dish. The wine, aromatics, and cheese will cause your palate to sing as it experiences acidity, aroma, fat, and salt, making it a hearty dish that flexes as both a party appetizer or a meal on its own. 


Roasted Leeks and Mushrooms with Cannellini Beans

  • Author: Brandon Hertzler


  • 4 large leeks
  • 1 8 oz. container of cremini mushrooms – torn into bite sized pieces
  • 1 Tbsp. olive oil
  • 2 Tbsp. flour
  • 4 large garlic cloves, minced
  • 1 ¼ c. whole milk
  • c. white wine
  • ½ tsp. dried thyme
  • 3 Tbsp. parmesan cheese – grated
  • 2 cans of cannellini beans, drained and rinsed
  • Salt and pepper to taste


  1. Preheat oven to 400 F
  2. Clean leaks by cutting them just at the point where they begin to flair turn from white to green. For a great tutorial on how to clean leeks, follow these great directions
  3. Tear the mushrooms by hand into bite sized pieces.
  4. Toss the mushrooms in a bit of olive oil and salt, then add them along with the leeks to a large baking sheet and roast for 30-40 minutes. Be sure to toss the mushrooms occasionally during cooking and rotate the leeks as well.  The leeks will be finished when they are browned on the outside and soft on the inside.
  5. Once the leeks and mushrooms are finished complete the sauce. Begin by heating olive oil in a skillet. Once the oil is hot, add the minced garlic and stir frequently. When the garlic is cooked, add the thyme, salt, pepper, and flour into the pan. Stir the ingredients together and cook for a minute or to cook off the flour.
  6. Next, begin to slowly add the white wine a little bit at a time with a whisk. Follow this with the milk. Bring the sauce to a gentle simmer, continuing to stir often for about 5 minutes. Stir in the parmesan cheese and add any additional salt or pepper you like, depending on your personal taste.
  7. Cut the cooled leeks in half lengthwise and scoop out the tender middle. Roughly chop up the leeks before adding them into the sauce along with the mushrooms and beans.
  8. Stir well to combine and bake them at 350 F for 15 minutes. Serve with bread or with pasta. If you want to make this more of a sauce, increase the milk by 1 cup or add a cup of broth back at step 6.

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