Potato Pierogi Pizza - Potato Goodness

Ingredients

• 1 envelope active dry yeast
• 1 cup warm water (110 degrees)
• 3¾ cups flour plus ½ C extra for kneading
• 1½ teaspoon salt
• 2 cups mashed potatoes
• 1 medium onion
• 1 clove garlic
• ½ cup olive oil
• 4 cups shredded sharp cheddar cheese
• 1 cup shredded mozzarella cheese (low moisture)
• ½ cup grated parmesan cheese
• 2 teaspoons salt
• 1 teaspoon pepper