Cook tortellini according to instuctions. Drain, set aside.
Slice chicken breasts horizontally so as you have 4 even pieces of chicken, dry with a paper towel. Sprinkle with cajun seasoning, coating thoroughly. Heat 2 tbsp olive oil in a cast-iron skillet over med-high heat till almost smoking. Cook chicken until very dark on first side, flip and cook till dark, turn down oven to med-low and cook for an additional 5-10 minutes. Remove from pan, set aside. Add onions,green and red peppers to pan, turn heat back up to med-high and cook for 4-5 minutes just until they are not raw. Add boursin cheese, cream, and parmesan cheese, turn down heat again and stir until cheeses melt. Cut up chicken into bite-size pieces and add to sauce. Pour tortellini into a big bowl and add chicken and vegetables. Stir and enjoy.