2. Add quartered mushrooms and chopped shallot to the pan. Saute until lightly brown and soft. Remove pan from heat and allow to cool for 10 minutes.
3. In a food processor, add the mushroom and shallot mixture, pine nuts, garlic, olive oil, broth, salt, pepper, and lemon juice. Pulse and process until mixture is finely ground, scraping down the sides of the processor as needed.
4. Remove mushroom mixture from the processor by scraping it into a mixing bowl. Stir in the parmesan cheese (adding the parmesan into the food processor can cause the cheese to melt and become stringy)
5. Stir pesto into freshly cooked penne pasta, add to the top of crostini, or use as a dip for Italian-seasoned pita crisps.