Make a paste with the flour, garlic and half the lemon juice. Coat the chicken with the paste and leave for half an hour.
Put a little olive oil in a sauce pan. Scrape the paste off the chicken and keep for the next step. Add the chicken and the fennel seeds to the pan and fry the chicken on each side.
If the paste is quite thick, thin it with a little water or stock then add it to the pan and stir with a wooden spoon. Then add the rest of the stock, sage, salt and pepper. Bring to the boil then lower to a very gentle simmer for about 20 minutes. Or, put in the oven at about 180°C for half an hour.
Mix the egg yolk with a little lemon juice. Remove the chicken from the pan. Stir in the lemon juice. Keep stirring as it thickens but don't let it boil.
Serve the sauce poured over the chicken with rice or potatoes and vegetables.
Nutritional information is approximate and a guideline only.