Preheat oven to 400º and line 2 baking sheets with parchment paper. Bring water, butter and salt to a simmer in a medium saucepan over medium heat.
Add flour all at once; stir quickly with a wooden spoon until flour forms ball and pulls away from the sides of the pan. Film will form on the bottom of the pan and dough will no longer be sticky; this usually takes 1-2 minutes.
Transfer dough to bowl of electric mixer and, using paddle attachment, beat in eggs one at a time. Stir in grated Gouda, thyme and pepper.
Drop dough by rounded tablespoonfuls onto baking sheets (a spring-loaded cookie dough scoop works well if you have one). Smooth down any errant peaks of dough with a wet finger.
Bake for 15 minutes, then rotate position of pans.
Bake an additional 15 minutes, until golden brown.
Serve warm or transfer to racks and cool
Rewarm in a 350º oven about 5 minutes.