Blend 1 1/2 cups water, 1 cup chickpea flour, 2 tablespoons olive oil and 3/4 teaspoon kosher salt in a blender. Let rest 15 minutes, then skim off the foam. Heat 2 tablespoons olive oil in a medium ovenproof nonstick skillet over high heat. Pour in the batter and cook until the bottom is set, 2 minutes. Sprinkle with sesame seeds and crushed coriander and cumin seeds. Bake at 425 degrees F until the pancake springs back when pressed, 20 minutes. Sprinkle with flaky salt.