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.