Cook pineapple, ground habanero, and half the water over medium heat until pineapple is quite soft. This may take up to 10 or even 15 minutes. If the water boils away before the pineapple is soft enough to produce its own juices to cook in, add the rest of the water. Keep stirring and mashing the pineapple to break it down as much as possible.
Whisk together pectin with 150 grams sugar, then measure out the remaining 150 grams sugar in a separate container and set both aside.
When the pineapple has softened and the water has mostly evaporated, use an immersion blender to pulverize it until no large chunks remain.
While stirring, add the pectin and sugar mixture to the pineapple. Add the lemon juice, and stir to combine. The mixture should begin to thicken pretty quickly. Then add the remaining 150 grams sugar and stir well.
Bring the mixture to a boil and cook, stirring constantly until desired consistency is reached.
To check the consistency, put a small dollop (about ¼ tsp) on a plate (not plastic) and stick it in the fridge for 30-60 seconds. Then try spreading it with a spoon or knife. If it's too liquid-y, keep cooking a little while longer. If it spreads like jam, it's done. You can keep cooking if you want a thicker jam but it will become firmer as it cools so better to pull it a bit early than cook it a bit too long.If it's still too chunky, you can use the immersion blender again at this point, just be careful because the sugar is quite hot!
Transfer the jam to a glass jar for canning, or to any airtight container for immediate use and storage.