Preheat the oven to 325 degrees F (163 degrees C).
Line a large baking sheet, or two small ones, with parchment paper.
(I used two 13x9 in (33x23 cm) cookie sheets.)Pulse almonds and hazelnuts in a food processor intermittently, until most of the nuts are in chopped into large pieces (about 1/4 to 1/2 of the full size of the nuts).Add the pecans.
Pulse again, stopping when the pecans are in large pieces.
(Pecans are added later since they are softer.)Add the pumpkin seeds, sunflower seeds, erythritol, and golden flaxseed meal.
Pulse just until everything is mixed well.
Don't over-process! You want to have plenty of nut pieces remaining, and most of the seeds should be intact.Add the egg white to the food processor.
Whisk together the melted butter and vanilla extract in a small bowl, and evenly pour that in, too.Pulse a couple times, mix a little from the bottom toward the top with a spatula, then pulse a couple times again.
Repeat as needed until everything is coated evenly.
Again, avoid over-processing.
At the end of this step, you'll have a combination of coarse meal and nut pieces, and everything should be a little damp from the egg white and butter.Transfer the nut mixture to the prepared baking sheet in a uniform layer, pressing together into a thin rectangle (about 1/4 to 1/3 in (.6-.8 cm) thick).
Bake for 15-18 minutes, until lightly browned, especially at the edges.Cool completely before breaking apart into pieces.
(The granola will be soft when you remove it from the oven, but will crisp up as it cools.)