Savory Free-Form Sweet Potato Tart

Preparation

1. Step 1

   Make the crust: Combine flour and salt in a food processor and pulse once or twice. Add butter and turn on machine; process until butter and flour are blended and mixture looks like cornmeal, about 10 seconds.

2. Step 2

   Put mixture in a bowl and add 3 tablespoons ice water; mix with your hands until you can form dough into a ball, adding another tablespoon or two of ice water if necessary; if you overdo it and mixture becomes sodden, add a little more flour. Form into a ball, wrap in plastic and freeze for 10 minutes or refrigerate for at least 30 minutes. (You can refrigerate for up to a couple of days or freeze for up to a couple of weeks.)

3. Step 3

   Meanwhile, make the filling: Put oil in a small skillet over medium-high heat. Add onion and cook, stirring occasionally, until softened, 2 or 3 minutes; add garlic, stirring constantly, and cook for another minute. Sprinkle with salt and pepper, then stir in chile powder and tomato paste. Cook and stir until fragrant, less than a minute; then toss with sweet potatoes. Set aside.

4. Step 4

   Heat oven to 375 degrees. Grease a large rimless baking sheet or line it with a piece of parchment paper.

5. Step 5

   Sprinkle a clean countertop with flour, put chilled dough on it, and sprinkle top with flour. Use a rolling pin to roll dough into a circle at least 12 inches in diameter, adding flour and rotating and turning dough as needed; it is O.K. if it's not perfectly round. Use ragged edges of dough to repair any tears, adding a drop of water while you press patch into place. (If dough is hard, let it rest for a few minutes. If dough is sticky, add a little flour; if it continues to become sticky and it is taking you more than a few minutes to roll it out, refrigerate or freeze again.)

6. Step 6

   Use rolling pin to transfer dough to prepared baking sheet. Toss sweet potato mixture again; taste and adjust seasoning if necessary. Carefully spread it on crust, leaving about 3 inches free all the way around edge. Fold sides up over filling. You should have a big circle open in top. Press down gently to flatten tart a bit.

7. Step 7

   Bake tart until crust is nicely browned and insides are bubbly, 45 to 50 minutes. Cool a bit before slicing or serve at room temperature.