Pre-cook the Potatoes: Place the cubed potatoes in a large pot, cover with cold water, and add a generous pinch of salt. Bring to a boil and cook for 8-10 minutes, or until slightly tender but not fully cooked. Drain well and set aside.

Sear the Chicken: Season the chicken pieces with salt, pepper, and red pepper flakes (if using). Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Working in batches, sear the chicken until golden brown on all sides. Remove the chicken from the skillet and set aside.

Crisp the Potatoes: Add the remaining 1 tablespoon of olive oil and 1 tablespoon of butter to the skillet. Add the pre-cooked potatoes and cook over medium-high heat, stirring occasionally, until golden brown and crispy on all sides. This should take about 10-15 minutes. Remove the potatoes from the skillet and set aside.

Make the Garlic Sauce: Add the remaining 1 tablespoon of butter to the skillet. Reduce the heat to medium. Add the minced garlic and cook for about 1 minute, or until fragrant, being careful not to burn it. If using flour to thicken the sauce, sprinkle it over the garlic and cook for another minute, stirring constantly.

Deglaze and Simmer: Pour in the chicken broth and scrape up any browned bits from the bottom of the skillet. Add the fresh thyme and rosemary sprigs. Bring to a simmer and cook for a few minutes, allowing the sauce to reduce slightly.

Create the Creamy Magic: Stir in the heavy cream and bring the sauce back to a gentle simmer. Season with salt and pepper to taste. If using Parmesan cheese, stir it in now.

Combine and Finish: Return the chicken and potatoes to the skillet. Stir to coat them evenly with the sauce. Simmer for another 5-7 minutes, or until the chicken is cooked through and the sauce has thickened to your liking.

Serve: Garnish with fresh parsley and serve immediately.