Prepare the Chicken: Cut the chicken fillets into bite-sized pieces, then season with salt and black pepper.

Cook the Chicken: In a large skillet, heat a splash of vegetable oil over medium-high heat. Cook the seasoned chicken until golden brown, about 5-7 minutes. Transfer to a plate and set aside.

Sauté the Veggies: In the same skillet, add the sliced red onion, mushrooms, and minced garlic. Sauté until the vegetables are tender, approximately 5 minutes.

Create the Sauce: Sprinkle the flour over the sautéed vegetables and stir to coat. Gradually add the chicken broth and milk, stirring continuously to avoid lumps. Let the mixture bubble gently until it thickens, around 3-4 minutes.

Combine Chicken and Sauce: Return the cooked chicken to the pan, mixing well to coat it with the sauce. Simmer for a few minutes to marry the flavors. Adjust seasoning with salt and pepper as needed.

Garnish and Serve: Just before serving, sprinkle the dish with freshly chopped parsley.

Make the Mashed Potatoes:

• Peel and dice the potatoes, then boil them in salted water until tender, about 15-20 minutes. Drain and set aside.
• In a separate pot, melt the butter and sauté the chopped onion until translucent.
• Add the cooked potatoes to the onion, mashing them and gradually incorporating the milk until creamy. Season with salt and pepper.

Final Touch: Serve the chicken dish alongside the creamy mashed potatoes, garnished with chopped dill.