Season chicken cubes with salt and pepper. Heat olive oil in a large skillet over medium-high heat. Sear chicken until golden brown and cooked through, about 5-7 minutes. Remove chicken and set aside.
In the same skillet, melt butter. Add shallots and sauté for 2 minutes until translucent. Add garlic, oregano, and red pepper flakes, cooking for 1 minute until fragrant.
Add the dry orzo to the skillet and toast for 2 minutes, stirring frequently to prevent burning.
Stir in the sun-dried tomatoes and chicken broth. Bring to a simmer, then reduce heat to medium-low. Cover and cook for 10-12 minutes, or until orzo is tender and most liquid is absorbed.
Stir in the heavy cream and parmesan cheese until well incorporated and creamy.
Fold in the cooked chicken and fresh spinach. Heat for 2 minutes until spinach is wilted.
Adjust seasoning with salt and pepper and serve immediately.