Add the chicken breasts and stock to a medium saucepan over medium heat. Bring to a simmer and cover, letting cook until the chicken is cooked through and tender.
Remove the chicken from the pan and let sit until cooled to the touch. Shred the chicken and set aside.
In a small bowl stir together the paprika, oregano, smoked paprika, cayenne and thyme.
In a large saucepan over medium heat add the butter and melt. Add the shallots and sauté until tender.
Add the spices then stir in the flour and stir to combine, letting it cook until the spices are fragrant, about 30 seconds.
Whisk in the chicken stock and bring to a boil. Lower heat and simmer until the mixture has thickened. Whisk in the cream and season with salt and pepper. Stir the shredded chicken into the sauce.
Heat a large sauté pan over med heat, add olive oil and heat. Add sausage and peppers, cooking until the sausage is golden brown. Add the collard greens and sauté until wilted.
Bring a large pot of water to a boil over medium-high heat. Salt the water and return to a boil. Add the penne pasta and cook, stirring occasionally, until al dente, about 10 minutes. Drain and return to the pot.
Add the Cajun sauce as well as the sausage and collard greens and stir to combine. Divide among serving bowls and garnish with green onion.