Heat a wide, low saucepan over medium-high heat. Place the 4 chicken legs skin-side down and sear for 6-8 minutes until golden brown. Flip and sear for another 4-5 minutes. Remove chicken and season with salt and white pepper.
In the same saucepan with the rendered chicken fat, add the 20 g flour and whisk over medium heat for 1-2 minutes to form a paste. Gradually add the 500 ml chicken broth while stirring constantly. Simmer for 2-3 minutes until the sauce slightly thickens. Season with the 1 tablespoon lemon juice and grated nutmeg to taste.
Preheat oven to 180°C (350°F). Return the chicken legs to the sauce. Cover and braise in the oven for 50 minutes, until the chicken reaches 74°C (165°F) internal temperature at the thickest part of the thigh.