In a large dutch oven or soup pot, heat the oil on medium high heat.
Add the onion, carrots and celery and season with a pinch of salt.
Saute for 5 minutes until vegetables begin to soften.
Add the garlic and saute one minute.
Add the tomato paste and saute until combined.
Add the flour and cook for another minute.
Stir in the mushrooms and season with another pinch of salt and pepper.
Add in the beer and broth and stir everything together.
Drop in the bay leaf, and season with the rosemary and thyme.
Bring to a boil and then simmer for about 45 minutes uncovered until the stew becomes thickend and vegetables are thouroughly cooked through.
Once the stew is cooked, turn off the heat and add in the kale.
Season with additional salt and pepper if needed and serve.