Activate the Yeast: Combine 1/2 cup warm water, 1/2 cup flour, and 1/2 teaspoon yeast in a small bowl. Whisk until dissolved and let sit for 5-10 minutes, until foamy.
Make the Dough: In a large bowl or mixer fitted with a dough hook, combine the remaining flour, water, yeast mixture, sugar, and salt. Mix until a shaggy dough forms, then knead for 10 minutes on a lightly floured surface, or until smooth and elastic.
Incorporate the Lard: Gradually add the melted lard, 1 tablespoon at a time, kneading until fully incorporated. Continue kneading for another 5 minutes, until the dough is soft and slightly sticky.
First Rise: Place the dough in a greased bowl, cover with plastic wrap, and let rise in a warm place for 1-2 hours, or until doubled in size.
Shape the Loaves: Punch down the dough and divide it into two equal pieces. Shape each piece into a tight log about 14 inches long.
Second Rise: Place the loaves on a greased baking sheet, seam side down, and cover loosely with plastic wrap. Let rise for another 45-60 minutes, or until slightly puffy.
Score and Bake: Preheat your oven to 400°F (200°C). Using a sharp knife, make 3 diagonal slashes on the top of each loaf. Bake for 30-35 minutes, or until golden brown and firm to the touch.
Cool and Serve: Transfer the bread to a wire rack and let cool completely before slicing. Enjoy your pan Cubano fresh, toasted, or piled high with the delicious fillings of a classic Cubano sandwich!