Makes 4 pizzas (each about 8-inches round)
For the crust:
3 cups unbleached all-purpose flour plus additional for dusting
2 teaspoons baking powder
1 teaspoon coarse kosher or sea salt
1 large egg, slightly beaten
Canola oil for brushing
For the toppings:
2 tablespoons canola oil
1 large potato, peeled, cut in half lengthwise, each half thinly sliced crosswise (coin-like) (see tips)
1 teaspoon coarse kosher or sea salt
8 ounces pre-washed fresh baby spinach leaves
2 fresh green Serrano chiles, stems discarded, thinly sliced crosswise (coin-like) (do not remove the seeds)
2 teaspoons Turmeric Trail's Madras Masala
2 cups store-purchased, tomato-based pizza sauce
4 cups assorted shredded cheeses (like mozzarella, cheddar, fontina, and romano)
To make the dough for the crust, thoroughly combine the flour, baking powder, and salt in a large bowl.
Pour the beaten egg over the flour mixture and quickly stir it in. The flour will still be very dry, with a few wet spots.
Pour a few tablespoons warm tap water over the flour, stirring it in as you go. Repeat until the flour comes together to form a soft ball; you will use about 1 cup warm water altogether. You want the dough to be very soft, close to being slightly sticky, so if you add an extra tablespoon or so, you won't ruin it. Using your hand (as long as it's clean, I think it's the best tool), gather the ball, picking up any dry flour in the bottom of the bowl, and knead it to form a smooth, soft ball of dough. If it's a little too sticky to handle, dust your hand with flour, but do not add any more flour to the dough if possible. Knead it for a minute or two. (If you used your hand to make the dough from the start, it will be caked with clumps of dough. Scrape them back into the bowl. Wash and dry your hands thoroughly, and return to the dough to knead it. You will get a much better feel for the dough's consistency with a dry hand.)
Cut the dough into 4 equal portions. Lightly grease a plate with oil. Shape one portion into a round resembling a hamburger bun, and put it on the plate. (To get a smooth round, cup the dough between the palms of your hands and use your fingers to fold and tuck the edges underneath; then rotate it, folding and tucking all around to get an evenly smooth ball.) Repeat with the remaining dough.
Brush the tops of the rounds with oil, cover them with plastic wrap or a slightly dampened cloth, and let them sit at room temperature for about 30 minutes. Allowing the dough to rest softens the gluten that has formed as you knead the dough. Gluten is what gives bread its structure, and when just formed, has a tendency to spring back into a tightness that makes it difficult to roll the dough.
As the dough rests get the toppings ready. Heat the oil in a large nonstick skillet over medium heat. Once the oil appears to shimmer add the potato slices and the salt and pan-roast them, uncovered, stirring occasionally, until they are sunny brown, slightly crispy on the outside, and just tender when cut with a fork, 12 to 15 minutes. Crank up the heat to high and add the spinach leaves, stirring briskly and constantly to wilt them without allowing them to rest in one spot long enough to release its water, 1 to 2 minutes. Stir in the chiles and turn off the heat.
If you plan to grill the pizza, place a pizza stone or unglazed pottery tiles on the grill rack. If it is a gas grill, heat it to the highest heat setting. If it is a charcoal grill, build an intensely hot fire and allow the charcoal to turn red-hot and ash-white. The temperature should hover between 600 and 700˚F. It is hard to generate that same intense heat in a kitchen oven because they are not designed to generate more than 550˚F, but you can bake the pizza in it if you don't have a grill (or if it's snowing outside). If yours is a conventional oven, place the pizza stone, unglazed pottery tiles, or a cookie sheet on the lowest rack and preheat it at the highest bake setting. A convection oven generates the same heat but distributes it more evenly, and you can place the pizza stone on any of the racks. You will need to bake the crust a little longer than you would on an outdoor grill.
Lightly flour a small work area near the grill, and place a dough round on it. Press it down to form a patty. Roll the patty out to form a round roughly 8 to 9 inches in diameter, dusting it with flour as needed. Make sure the round is evenly thin, with no tears on the surface. Lift the round (here is where a wooden paddle that often comes with a pizza stone kit comes in handy) and slide it onto the hot pizza stone. Within seconds, the dough will start to bubble in spots. Ladle 1/2 cup pizza sauce on the dough and spread it evenly to cover almost the entire surface, leaving about 1/2-inch dough bare around its peripheral. Spread a quarter of the vegetable topping over the sauce. Cover the grill and cook until the dough turns crispy brown on the underside and the edge acquires light brown patches, 3 to 4 minutes. Lift the cover and spread 1/2 cup shredded cheese atop the vegetables. Place the cover back on the grill and let the cheese melt, about 1 minute. Lift the pizza from the stone onto a cutting board and slice it as desired. If you are using an oven allow yourself another 3 to 5 minutes to brown the crust.
Repeat with the remaining dough, sauce, vegetables, and cheese. Serve each pizza as soon as they are ready.