1. Preheat broiler with oven rack 8 inches from heat. Place cauliflower in a 15- x 10-inch jelly-roll pan. Drizzle with olive oil, and sprinkle with black pepper and 1/4 tsp. sea salt; toss to coat.
2. Broil cauliflower 10 minutes or until lightly browned, stirring halfway through. Remove from oven; cool in pan on a wire rack 30 minutes.
3. Whisk together cornmeal, next 3 ingredients, and remaining 1 tsp. sea salt in a medium bowl. Whisk together eggs, yogurt, and 1 cup water; whisk into dry ingredients. Fold in cheese and half of onions. Fold in cooled cauliflower.
4. Drop half of batter by spoonfuls (about 2 Tbsp.) into 2 Tbsp. hot vegetable oil in a nonstick skillet over medium-low heat (do not crowd pan), and fry 3 to 4 minutes on each side or until golden. Drain on paper towels. Repeat with remaining batter and oil. Sprinkle with remaining green onions.
5. Stir together chipotle peppers and crème fraîche; serve with galettes.
Brought to the table by cookbook author Ellise Pierce (adapted from Cowgirl Chef cookbook).