Tomato Galette - Oryana

Ingredients

• 1-1/4 cups all-purpose flour
• 1/3 cup masa harina
• 1/2 teaspoon sea salt
• 1 stick butter, cut into 1/2-inch pieces, chilled
• 1/4 cup ice water
• 2 tablespoons olive oil
• 1 large onion, thinly sliced
• Salt and freshly ground black pepper
• 2 cloves garlic, chopped finely
• 1/3 cup chopped fresh basil, plus whole leaves for garnish
• 1 cup corn
• 1 large or 2 medium ripe tomatoes (about 3/4 lb. total) cut into 1/3-inch slices, drained on paper towels
• 3 oz. aged Provolone cheese, shredded
• 1 egg, beaten