Place an oven rack in the center of the oven. Heat the oven to 400°F (205°C).

To a medium bowl, add the flax seeds, boiling water, and a hefty pinch of salt. Stir and set aside for a minute or so, until the seed mixture goes from a liquid consistency to a gloopy, egg white-like consistency.

Add the remaining 2 cups of mixed seeds to the mixture and stir to combine. Taste and season with a little bit more salt if needed.

Lightly grease a half sheet pan with oil. Line with a sheet of parchment paper on the bottom.

To the pan, add 2 tablespoons of oil. Using a pastry brush or your hands, evenly spread the oil on the surface.

Dollop the seed cracker mixture on the pan and evenly spread using a spatula in a thin, even layer that covers the surface of the pan.

Using a pastry brush, brush the remaining 2 tablespoons of oil on top of the seed cracker mixture. Sprinkle with salt on top.

Bake for 25 to 28 minutes, until the seeds start to look golden. Make sure to keep an eye on the oven and check on the seed crackers every now and then.

Open the oven door to release some of the heat and reset the temperature to 350°F (175°C). Rotate the sheet pan, close the oven door, and continue baking for 12 to 15 minutes, until the seed crackers look golden brown.

Transfer the crackers to a cooling rack or allow them to cool in the pan. Snap the seed cracker bark into smaller pieces and the seed crackers are ready!

Store in an air-tight container for 2 to 3 weeks.