Place soaked nuts and seeds in food processor with onions, carrots, and mushrooms and process with “S blade” until finely chopped and somewhat sticky. It should resemble traditional bread stuffing after the bread has been moistened.
Remove from processor and set aside in a large bowl.
Pulse chop parsley, celery and scallions in food processor with S blade until finely minced. Add to nut vegetable mixture.
Pulse-chop pecans in food processor to about 1/8 inch pieces.
Add pecans, herbs, salt and lemon juice to bowl.
Mix well with wooden spoon or hands. The mixture should hold together.
Adjust seasonings to taste: rosemary, thyme, sage, parsley, salt, pepper, garlic.
Arrange on a serving platter and serve as is, or put in dehydrator overnight to warm through and create a crusty exterior with a moist interior. You’ll need to remove some of the dehydrator trays to fit the platter of stuffing.
If you prefer a crispier stuffing, dehydrate the stuffing as a 1-inch thick patty and crumble in a bowl before serving.