Make the seasoning paste: mix 1 tablespoon lemon juice or water with the hot and sweet paprika powders and 4 cloves of pressed or minced garlic.
Wash the chicken pieces and pat dry. Rub the seasoning paste all over the chicken. Refrigerate until ready to cook.
Preheat the oven to 200°C (392°F) with top and bottom heat only—do not use fan/convection.
Heat 40 ml oil in a large casserole on medium heat. Add the diced onions and fry for 2-3 minutes without browning them.
Increase heat to medium-high. Add the chicken pieces and fry on both sides for 5 minutes total until lightly browned. Season lightly with salt.
Pour 250 ml water into the casserole. Place uncovered in the oven and cook for 30 minutes with the chicken legs positioned down.
While the chicken cooks in the oven, prepare the cream sauce: mix the crème fraîche, Greek yogurt, tomato paste, and flour until smooth. Whisk in 250 ml water until the sauce is smooth.
Remove the casserole from the oven and flip the chicken pieces. Pour the cream sauce over the chicken. Return to the oven uncovered and cook for 30-40 minutes until the chicken reaches 74°C (165°F) internal temperature at the thickest part.