In a medium-sized bowl mix the yogurt with 1 ½ cups flour, making a moist dough.
Knead in the nut or seed butter (or vegan butter or oil), one tablespoon at a time.
Take two sheets of parchment paper. Lightly flour one sheet and place the dough on top and pat it down into a circle.
Sprinkle more flour on top and cover with the other sheet of parchment paper.
Roll the dough into an 11-12 inch circle about ⅛ inch thick.
Remove the top sheet.
Lift the bottom sheet of parchment paper with the dough and carefully flip into a 9-inch tart pan.
Carefully peel off the parchment paper and press dough into tart pan.
Do not panic if the dough tears, you can press it back together.
Trim the edges to ½ inch all around.
Fold the edges under and crimp the dough.
Dough may be used immediately or refrigerated until ready to use.