Heat 2 tablespoons olive oil in a dutch oven over medium-high heat. Cook the chicken and sausage through, about 6-7 minutes. Drain meat and set aside.
Add onion, celery, and jalapeno to the dutch oven and cook until softened. Add garlic and cook for another minute.
Stir in flour and cook for 1-2 minutes.
Gradually whisk in chicken broth and beer, scraping up any browned bits from the bottom of the pot.
Bring to a simmer, then add diced tomatoes.
Return the cooked chicken and sausage to the pot.
Simmer for at least 30 minutes, or longer for a richer flavor.
Add shrimp and cook until pink and opaque, about 5-7 minutes.
Season with Cajun seasoning to taste.