In a saucepan, mix the cold fruit purees with the water. At the same time, weigh out the dry ingredients (Pectin NHX, Natur Agrum, Warmtex and brown sugar). Whisk the dry ingredients into the liquid, then bring to the boil, stirring constantly to prevent the mixture sticking to the bottom of the pan. Pour the mixture over the coconut oil and cocoa butter, then blend using a hand blender to perfect the emulsion. Cool quickly before use.Once the cream has cooled, pipe into a pastry bag using a 10 mm plain tip. Poach into the base of the tartlets.