Preheat oven to 350°F. Line a baking sheet with parchment paper.
In a large bowl, whisk together: Sunflower seed meal, Baking powder, Garlic powder, Onion powder, Thyme, Parsley, Black pepper, Salt.
Add wet ingredients: Eggs, Parmesan, Gruyère. Mix until a thick dough forms. The dough should hold together easily.
Transfer dough to the prepared baking sheet. Shape into a log about 10 inches long and 3 inches wide.
Bake for 20–22 minutes, until firm and lightly golden. Remove from oven and let cool 10 minutes.
Using a serrated knife, slice into ¾-inch thick biscotti.
Lay biscotti slices cut-side down on the baking sheet. Bake 12–15 minutes total, flipping halfway, until crisp and golden. Let cool completely — they crisp more as they cool.
Store in an aluminum foil or airtight container at room temperature for up to 2–3 days. Freeze up to 3 months.
To re-crisp: bake uncovered at 325°F for 7–10 minutes, then cool.