Heat olive oil in a large skillet over medium-high heat.
Add the chicken pieces to the skillet and cook for 5-6 minutes, stirring occasionally, until browned and cooked through. Remove chicken from the skillet and set aside.
In the same skillet, add the diced onion and cook for 3-4 minutes until softened.
Add the minced garlic and cook for 30 seconds until fragrant.
Pour in the chicken broth and bring to a boil.
Add the egg noodles to the boiling broth, reduce heat to medium, and cook for 8-10 minutes, stirring occasionally, until noodles are tender.
Return the cooked chicken to the skillet and stir to combine.
Pour in the heavy cream, then add dried thyme, dried parsley, salt, and black pepper. Stir well to combine.
Cook for an additional 3-4 minutes, allowing the sauce to thicken slightly.
Stir in the shredded cheddar cheese until melted and the sauce is creamy.
Add the chopped baby spinach and cook for 1-2 minutes until wilted.
Remove from heat and serve immediately.