Easy Cajun Jambalaya

In a large pot over medium heat, heat oil. Add onion and bell peppers and season with salt and pepper. Cook until soft, about 5 minutes, then stir in chicken and season with salt, pepper, and oregano. Cook until the chicken is golden, about 5 minutes, then stir in andouille sausage, garlic, and tomato paste and cook until fragrant, about 1 minute more. Add chicken broth, crushed tomatoes, rice, and Old Bay. Reduce heat to medium low, cover with a tight fitting lid, and cook until the rice is tender and the liquid is almost absorbed, about 20 minutes. Add the shrimp and cook until pink, 3 to 5 minutes. Stir in green onions just before serving.