Combine the lemon juice, mustard, garlic and white pepper. Beat in 5 tablespoons (100ml) of the olive oil. Put the chicken in a shallow container and pour the lemon mixture over it. Cover and refrigerate for at least 1 hour.
In a large frypan, saute the almonds in 1/2 tablespoon (10ml) of the olive oil until golden. Remove from frypan and reserve. Wipe out the frypan. Drain the chicken, reserving the lemon marinade. Add remaining 1 tablespoon olive oil to frypan then add chicken breasts and brown over high heat until breast is brown on each side (6 to 10 minutes). Remove from frypan and reserve.
Strain the lemon marinade into the frypan. Bring to a boil and boil for 1 minute. Add chicken stock and cornflour/water mixture. Cook over high heat, stirring occasionally, until the mixture reduces by half (about 5 minutes). Add marmalade and stir over medium heat until melted. Stir in the butter a bit at a time over high heat, stirring constantly. Stir in parsley and red chilli flakes. Return chicken to frypan and heat through. Add reserved almonds and garnish with lemon slices.
The nutrition data for this recipe includes information for the full amount of the marinade ingredients. Depending on marinating time, ingredients, cooking method, etc., the actual amount of the marinade consumed will vary.