Rinse the chicken thighs with cold water, pat dry with paper towels. Season the chicken thighs with salt, pepper and paprika, on both sides of the chicken. Transfer the chicken to a big bowl, add the lemon juice and parsley to the chicken.
Heat up a skillet and add a little oil. Pan-sear both sides of the chicken until nicely browned (but not cooked through). Dish out and set aside. Add the remaining oil to the skillet, saute the garlic and onions until the onion is slightly softened.
Add the potatoes, salt and brown sugar, stir to combine well. Transfer the chicken (and the juice that seeps out) into the skillet, arrange in between the potatoes and onions.
Bake the chicken and potatoes in the lower third of the oven for 30-40 minutes, or until the potatoes are cooked through. Serve immediately.
Notes
If the surface of the chicken gets too dark, cover it with aluminum sheet while baking.