Heat olive oil in a large skillet over medium heat. Add ground chicken and cook until golden brown, about 6-8 minutes.

Add chopped onion and bell pepper to the skillet. Sauté for about 5 minutes until softened. Then add minced garlic and cook for an additional minute.

Sprinkle Cajun seasoning over the mixture. Add diced tomatoes, tomato paste, and Worcestershire sauce. Stir well to combine.

Reduce heat to low and let the mixture simmer for 5-10 minutes. Season with salt and pepper to taste.

Assemble the sloppy joes by spooning the chicken mixture onto the bottom half of each bun. Top with chopped green onions and place the top half of the bun on each sandwich.