Pat the chicken pieces dry with kitchen paper and season lightly with salt. Dry skin helps achieve better browning and flavour. Set aside while preparing the base.
In a wide heavy casserole, heat the lard over medium heat. Add the finely chopped onions and cook slowly for 12 to 15 minutes, stirring often, until soft and translucent. They should melt rather than brown. This forms the soul of the sauce.
Remove the pan briefly from the heat. Stir in the sweet paprika and optional hot paprika, mixing quickly so it blooms in the fat without burning. Paprika scorches easily, so work swiftly before returning the pan to the hob.
Stir in the diced green pepper, tomato and crushed garlic. Cook gently for 5 minutes until slightly softened. This adds freshness and balances the richness before adding the chicken.
Place the chicken pieces into the pan, skin side down first. Turn to coat them thoroughly in the paprika base. Allow them to seal lightly for several minutes, absorbing flavour before moving to the next stage.
Pour in the chicken stock, ensuring the liquid comes halfway up the chicken but does not submerge it entirely. Cover and simmer gently for 35 to 40 minutes, turning once, until the chicken is tender and fully cooked.
In a small bowl, mix the sour cream with the plain flour until smooth. This prevents curdling and thickens the sauce evenly. Take a spoonful of hot cooking liquid and stir it into the cream mixture to temper it.
Remove the chicken pieces briefly from the pan. Stir the tempered sour cream mixture into the sauce over low heat until thickened and silky. Do not allow it to boil. Return the chicken to the sauce and warm through gently.
While the sauce finishes, cook the nokedli or egg noodles in salted boiling water according to instructions. Drain well and keep warm, ready for serving.
Arrange the chicken over a bed of nokedli and spoon the paprika sauce generously on top. Scatter with fresh parsley for colour and freshness. Serve immediately while the sauce is glossy and warm. A crisp cucumber salad on the side complements the richness beautifully.