Cast-Iron Personal Veggie Pizza

To prepare dough: Whisk water, honey and yeast in a medium bowl. Let stand until the yeast is bubbly and foamy, about 5 minutes. Add 2½ cups flour, 1 tablespoon oil and 1 teaspoon salt; use a spatula to mix well. Sprinkle the remaining 2 tablespoons flour on a clean countertop. Transfer the dough to the prepared surface; knead until smooth, about 5 minutes. Roll the dough into a ball and return to the bowl; cover with a warm towel. Set aside in a warm place, free from drafts, and let rise until doubled in bulk, 45 minutes to 1 hour.

Meanwhile, prepare sauce: Combine tomatoes, water, oil, basil, garlic and salt in a blender. Process until roughly blended, 10 to 15 seconds.

Heat a 2-quart saucepan over medium heat; pour the tomato mixture into the pan. Stir in tomato paste. Increase heat to medium-high heat; cook, stirring, until the mixture thickens and reduces to about 3½ cups, about 20 minutes.

To assemble pizza: Preheat oven to 450°F. Punch down the dough and divide it into 8 even pieces. Press 1 piece of the dough into an even layer in the bottom of a 5-inch cast-iron skillet. (Reserve remaining dough; see Tip to freeze.) Spread ¼ cup of sauce over the dough (see Tip for freezing extra sauce). Top with mushrooms, spinach, mozzarella and onion.

Bake until the crust is golden and cooked through, 15 to 20 minutes. Let cool for about 5 minutes before serving.