Tuscan Kale and Red Pepper Focaccia

Name: Tuscan Kale and Red Pepper Focaccia
Ingredients: 2 1⁄4 tsp. instant dry yeast (not active dry); 1 tbsp. honey; 3 cups all-purpose flour, divided, plus more for kneading; 3 medium russet potato (9 oz.); 1⁄4 cup plus 2 Tbsp. extra-virgin olive oil, plus more for greasing; 1 tbsp. kosher salt; 1 cup semolina flour; 2 cups (2 oz.) Tuscan kale (also called lacinato or dino), half finely chopped, half torn into large pieces; 1⁄2 tsp. red pepper flakes, or more to taste; 1 1⁄2 tsp. flaky sea salt