Combine water, yeast and sugar in a large mixer bowl and let stand 10 minutes. Add 2 cups flour, oil and salt. Beat for 3 minutes until very smooth. Stir in enough of the remaining flour to make a stiff dough. Knead on lightly floured surface until smooth and elastic, about 10 minutes. Place dough in a large greased bowl, turning to coat. Cover and let rise in a warm, draft-free place until almost doubled in bulk, about 1 hour.
Preheat grill to medium-low.
Punch dough down and divide into 2 parts; return 1 part to the bowl and cover. Divide remaining part into 8 pieces. Using lightly floured hands, pat out one piece of dough at a time on a floured board, into a 6-inch circle (1/8 to 1/4-inch thick); OR roll into a 6-inch circle with a rolling pin. Spray both sides of each circle with cooking spray. Place on hot grill. Close grill lid and grill 2 to 4 minutes, until lightly browned on bottom. Turn and grill an additional 2 to 4 minutes. Repeat with remaining dough. If using for pitas, cut flat breads in half and open up “pocket” with sharp knife.
Make-Ahead Directions: After rolling dough into circles, place on baking sheets lined with plastic wrap (circles may be stacked, using plastic wrap to separate). Keep refrigerated up to 3 hours before grilling.
-Whole wheat flat breads can be made by substituting 2 cups whole wheat flour for part of the all-purpose flour.
-For additional flavor, sprinkle flat breads with garlic salt and Italian seasoning before grilling.
-Flat breads may be frozen after grilling.