Combine 3 cups of bread flour, 1 teaspoon sea salt, and 1 teaspoon active dry yeast in a large bowl. Slowly add 1 ¼ cups of room temperature water, mixing until well-combined. Cover and let rise at room temperature for 8-12 hours.

Preheat oven to 400°F (200°C). Heat 2 tablespoons of olive oil in a skillet over medium heat; sauté 1 sliced onion for 5 minutes. Add fresh thyme during the last minute. Slice firm potatoes thinly, toss with olive oil, salt, and thyme, and roast for 15 minutes.

Heat a cast-iron skillet over high heat. Shape risen dough into 8-inch rounds. Broil each round for 1-2 minutes until light brown. Brush each base with garlic oil.

Layer each pizza with sautéed onions, roasted potatoes, and blue cheese. Return to broiler for 3-5 minutes until cheese is melted and bubbly.

Remove pizzas from oven, let cool for a minute, slice and serve warm.