Preheat the oven to 300℉ and line 2 baking sheets with parchment paper or a silicone baking mat.
To a medium bowl, add the flax seeds, chia seeds, and boiling water. Stir and set aside for 5 to 10 minutes or until the seed mixture changes from a liquid consistency to a gloopy, egg-white-like consistency. Add in the rest of the seeds: the sunflower seeds, pumpkin seeds, sesame seeds, and hemp hearts. Add in the salt and your herbs of choice, and mix until everything is evenly distributed.
Transfer your seed mixture to the prepared baking sheets. Spread it into a thin layer—about ⅕”-⅙” thick. Make sure to divide the mixture as evenly as possible between the two baking sheets.
Place on the center rack in the oven for 1 hour and 15 minutes. After 45 minutes, take the crackers out and brush them with the oil. At the same time, if you would like, you can slice into cracker shapes using a knife, pasta cutter, or pizza cutter. Otherwise, you can wait until the end of baking and just break up the sheet into cracker shards.
Adjust the baking time, either more or less time, depending on how browned, golden, and crispy you want the crackers. Keep an eye on them towards the end of baking so they don't burn.
Remove the crackers from the oven and let them cool completely. Break the crackers into pieces – either uneven pieces or, if precut, separate along the cut lines.
Storage Instructions: Store your seed crackers in an airtight container at room temperature for up to two weeks. If they happen to lose their crunch due to humidity, simply pop them back into a 300°F oven for 5 minutes to crisp them back up.