In a small bowl, mix the yeast, salt, sugar and water in a bowl. Lightly mix to dissolve the sugar. Allow the yeast to proof for about 5 minutes. You should see a nice layer of froth over the water. If not, try using fresher yeast.
In a large bowl, mix the flour and butter using a pastry cutter until the mixture looks like large crumbs.
Mix the yeast mixture into the flour mixture and combine well. Turn out into a floured surface and knead about 5 minutes. Put the dough back into the bowl and cover with plastic wrap and allow it to rise for 30 - 45 minutes.
Divide the dough into 10 pieces and roll out each piece into a circle about 4 inches in diameter. Place an even amount of the spinach and brie in the center of the rounds. Top with ground pepper and a pinch of dried garlic. (powdered garlic will work too)
pinch the edges together so the mixture will not melt out. Lightly roll each roll to smooth it out.
Line a baking sheet with parchment paper and place the rolls on. Put the sheet in the refrigerator uncovered for about an hour.
Preheat the oven to 425 degrees. Boil water in a large pot and add baking soda - be careful to not let it overflow. You should use 1.4 cup baking soda for every cup of water you use. Boil both sides of the rolls for exactly one minute each and place back on the baking sheet.
Lightly sprinkle the pretzel salt over each roll and bake for about 15 minutes, or until a nice deep brown.