• Find a large mug around 250ml in volume. Add the butter, sugar, flour, lemon zest and egg and mix very well with a dessert spoon. Set aside in a separate bowl and clean your mug.
• Peel the orange and slice the peel into very thin strips. Place in a small pan along with the sugar and water. Simmer until it has a sticky consistency and place into a bowl to cool down.
• Put the lemon zest and juice, the sugar and the butter into a heatproof bowl.
• Sit the bowl over a pan of gently simmering water, making sure the water is not touching the bottom of the bowl. Stir the mixture every now and then until all the butter has melted.
• Lightly whisk the eggs and egg yolk and stir them into the lemon mixture. Whisk until all the ingredients are well combined, then leave to cook for 10-14 minutes, stirring every now and again, until the mixture is creamy and thick enough to coat the back of a spoon.
• Remove the lemon curd from the heat and set aside to cool until completely cold.
• With a sharp knife, cut the top and bottom off the orange and carefully peel the outside skin and pith (the white bits), leaving just the flesh. Cut into segments.
• Sift 300g of icing sugar over 1 lightly beaten egg white. Stir until the mixture is a thick, pliable icing and roll into balls. Line a plate with kitchen paper.
• Put 5 broad bean-size balls on the plate and microwave on high for 60-90 seconds and watch as the balls balloon and puff into meringues. Set aside to cool.
• Place a large tablespoon of your chilled lemon curd at the bottom of your chosen mug and then top with the sponge mix. Place in the microwave on full power for around 60-90 seconds. It should feel firm and spongy to the touch. Remove from the microwave.
• Place 3 microwaved meringues to the side of the mug and then place a good dollop of lemon curd and your segments of orange to the other side.
• Finally, drizzle over your orange zest confit garnish with some mint leaves, get a spoon and tuck in!