Slice beef, place in bowl with oil and spice, then set aside.
Slice chicken, place in bowl with oil and spice, then set aside.
Cut all vegetables, place in a large bowl with oil and spice and set aside.
To make the Creamy Herbed Sauce, combine the yoghurt, mayonnaise and Chimichurri in a medium bowl and mix well. Transfer into a dipping bowl and set aside.
Pour vegetable stock into a fondue pot (do not overfill) or double handled cast iron pot and bring to a simmer on your stovetop.
To make the mustard sauce, place butter, mustard and Worcestershire sauce in a pan and warm over medium heat until butter is melted. Stir through Herbes de Provence. Pour into dipping bowl and serve hot.
Arrange your sauces on the table, put the marinated beef, chicken and vegetables on three separate platters. Ideally, provide two Fondue forks per guest, as well as two small plates per person (one for the raw ingredients and one for the cooked food, unless you own proper Fondue plates.
Once everything is ready and your guests are seated, carefully transfer your Fondue pot to the table and onto the rechaud. Light it and regulate the temperature according to the system you work with. Every guest should put some sauces and other accompaniments onto their 2nd plate, then put the raw foods onto the forks and dip into the broth until cooked to their liking.
Most Fondue pots have a lid-like ring with grooves in which the colour-coded forks can rest during the cooking process. A fork and knife is used to eat with, the Fondue forks are only used for dipping into the pot.