Add all ingredients, including the agar agar, to a high-powered blender and blend until completely smooth. The mixture will be very thick, so you may need to stop and scrape down the sides several times to get everything moving.
Transfer the mixture to a large saucepan over medium heat. Stir continuously with a spatula, making sure to scrape along the bottom and sides of the pan.
Continue cooking and stirring until the mixture becomes extremely thick and forms a thick, foldable mass that pulls away from the sides of the pan (this will take about 2-3 minutes). The tapioca starch will transform as it heats, giving the mixture its stretchy, cohesive texture. Because the mixture is so thick, it may not come to a conventional boil. The important thing is that it is thoroughly heated and the tapioca has activated.
Immediately transfer the hot mixture to a silicone container, or a lined loaf tin. Press and smooth the mixture firmly into an even block.
Refrigerate for approximately 4 hours, or until completely firm and chilled.
Once set, remove from the mould and slice into 5 strips, turning on its side, and cutting in half again (we find this makes 10-12 large pieces, with 2 large pieces being one portion). Cook however you like. For griddled slices, place in a sandwich press and cook at 180c/350f for 3–4 minutes, or until golden and brown.
For our hot honey version, cut the halloumi into small pieces and pan-fry with a little olive oil. Add our hot honey sauce and cook until the pieces are coated and golden.
