Heat 2 tablespoons olive oil in a large skillet over medium-high heat.
Add the 1 lb chicken thigh pieces to the hot skillet and sprinkle with Italian seasoning, salt, pepper, and red pepper flakes.
Sauté the chicken, stirring occasionally, for about 5 to 6 minutes until browned and cooked through; transfer to a plate and set aside.
Reduce heat to medium and add 2 tablespoons butter to the same skillet; when melted, add the sliced cremini mushrooms.
Season mushrooms with onion powder and garlic powder and cook, stirring, for about 4 minutes until they begin to brown.
Return the cooked chicken and any accumulated juices to the skillet, add the remaining 2 tablespoons butter and the minced garlic, and stir to combine.
Cook everything together for 1 to 2 minutes more, taste and adjust seasoning if needed, then remove from heat.
Garnish with chopped parsley and serve warm.
