I used Red Star Platinum yeast, but you can use regular yeast. The Platinum will give a better rise.
If you use a different brand of active dry yeast, let it bloom for a few minutes in the water before kneading. If you use any type of Red Star yeast, you don't need to wait.
Long Loaves
1 cup lukewarm water
1 packet (2 1/4 teaspoons) Red Star Platinum yeast
1 tablespoon sugar
1/2 cup (3 ounces) semolina flour
2 cups (9 ounces) bread flour
1/4 cup instant mashed potato flakes
Combine all ingredients in the bowl of your stand mixer fitted with the paddle attachment. Knead with the dough hook until the dough is smooth and elastic.
If you don't have a stand mixer, you can mix the dough in a bowl, then turn it out and knead by hand.
Cover the bowl with plastic wrap and let the dough rise until doubled, about an hour.
When the dough has risen, flour your work surface and line 2 baking sheets with parchment paper. Preheat the oven to 350 degrees.
Turn the dough out onto your work surface and divide in half. Form each half into a rope about 13 inches long. Place one rope on each baking sheet on a diagonal to give them plenty of space.
Cover the loaves with plastic wrap. Or, what I do is use a second baking sheet upside-down on top of the sheets with the rising bread. Set aside until the dough has doubled in size and if you poke one gently, the dent remains or fills in slowly.
Remove the plastic wrap and bake at 350 degrees until the loaves are nicely browned, about 25 minutes.
Remove the bread and let it cool completely on a rack before slicing.