Blend firm tofu, nutritional yeast, pumpkin purée, carrot, fried seaweed, water, and coconut milk until smooth.
Add salt, lemon juice, agar-agar powder, and tapioca starch. Blend until smooth.
Heat a large saucepan over medium heat. Add cheese mixture to pan, scraping any stubborn mixture from the blender.
Heat cheese mixture, stirring continuously until it starts to stick together. The mixture should start to turn thick and stretchy.
Pour mixture into a mold, cover, and refrigerate. Leave to cool and set for at least 2 hours, or overnight.
When ready, the cheese should be firm to touch. Best enjoyed sliced, shredded, or grated.