Cut the Seville oranges in half and juice them, adding the juice to the pan and reserving the orange halves.

Cut each juiced orange half into three long wedges.

Flatten the orange wedge with the skin side against the cutting board. Holding a small knife parallel to the orange skin, run the knife along to remove most of the flesh and pith. make several passes if needed until all pith is removes from shell leaving just the orange peel.

Add the pith, seeds and orange pulp to a bowl lined with a muslin cloth, keeping the peel separate.

Cut each piece of orange peel into fine shreds, and add to the juice in the pan.

Juice all of the juicing oranges, and and this juice to the pan.

Juice the two lemons and add the lemon juice to the pan.

Add 2 litres of water to the muslin pan.

Tie the muslin cloth firmly with string and submerge in the pan. Place pan into the fridge for 24-48 hours.

Place saucers or bowls into freezer to start them chilling.

Start sterilising the jars by washing them thoroughly.

Tie the muslin parcel so that it is not touching the very bottom of the pan, and start to heat the liquid. give the contents and occasional stir.

Once the contents start to simmer, set a timer for 40 minutes. Check occasionally to make sure that the muslin parcel remains off the bottom of the pan, and to gently agitate contents.

After 40 minutes, squeeze a bit of peel between fingers. It should be very soft and fall apart as it is squeezed. If it still remains a little tough, simmer for an additional 10 minutes.

Once peel is soft, turn off heat and remove muslin parcel into a bowl, or into a jam strainer set about a bowl. Leave to cool for 20 minutes.

Return to the muslin parcel and squeeze the contents thoroughly to release as much pectin as possible. Add the pectin-rich liquid back into the pan and stir. Discard the muslin contents.

Place Jars in a 180℃ oven to sterilise. Place metal lids into a saucepan and boil gently.

Add sugars to the jam pan and heat gently, stirring to completely dissolve sugar, being careful it does not catch on the bottom of the pan.

Once all sugar is dissolved, increase the temperature. Bring up to a rolling boil of 105℃ (to set the marmalade). Watch for bubbles that look like rapidly blinking fish eyes.

Once the temperature has been held for 60 seconds, turn heat to low and put a teaspoon of hot marmalade onto one of the frozen saucers. leave for 60 seconds and push gently with finger to see if a wrinkled skin is formed. If not, boil a little longer.

Once marmalade has reached the set point, turn off heat and leave for 20 minutes. so that peel doesn't float to the top when decanted.

Once ready to be put into jars, remove the jars from the hot oven and set them the right way up. Use a ladle and jam funnel to help decant the marmalade onto jars, ensuring it reaches up to the jar neck.

Top with a wax disc (wax side down) and seal with a sterilised lid.

Leave to set for 48 hours.