Mix the flour with salt and pepper. Dredge the pork shanks in the flour mixture.
Add vegetable oil to a large dutch oven over medium-high heat. Sear the pork shanks for about 2 minutes per side. Remove from the pan and set aside.
Add the celery, carrots, onions, mushrooms and potatoes to the pot. Cook the vegetables over medium heat for about 5 to 7 minutes until lightly cooked.
Add the beer, reduce the heat and deglaze the pan by scraping up all of the browned bits at the bottom of the pan.
Add the stock, herbs, salt, cracked black pepper and tomato paste to the pot.
Allow the mixture to simmer over medium heat for about 5 minutes.
Add pork shanks into the pan.
Cover the pot with aluminum foil and place into a preheated 325°F oven. Cook for about 3 hours.
Serve the pork shanks with the sauce, veggies, and your choice of sides. Enjoy!