Onion Anchovy Galette

Ingredients

• 5 fillet anchovy 
• 0.5 teaspoon thyme dried crumbled
• 1.3 cups flour all-purpose
• 1  garlic clove 
• 3 tablespoons water 
• 2 tablespoons olive oil 
• 2 large onion sliced (2 pounds total)
• 0.3 teaspoon salt 
• 2 tablespoons tomato paste 
• 2 tablespoons butter unsalted

Equipment

• food processor
• bowl
• frying pan
• baking sheet
• oven
• blender
• plastic wrap
• rolling pin
• dough scraper

Directions

1. Blend together flour, butter, and salt in a bowl with your fingertips or a pastry blender (or pulse in a food processor) just until most of mixture resembles coarse meal with some roughly pea-size butter lumps.
2. Drizzle 3 tablespoons ice water evenly over mixture and gently stir with a fork (or pulse in processor) until incorporated.
3. Squeeze a small handful: If it doesn't hold together, add more ice water, 1/2 tablespoon at a time, stirring (or pulsing) until incorporated, then test again. (Do not overwork mixture or pastry will be tough.)
4. Turn out mixture onto a lightly floured surface and divide into 4 portions. With heel of your hand, smear each portion once or twice in a forward motion to help distribute fat. Gather dough together, with a pastry or bench scraper if you have one, and press into a ball, then flatten into a 5-inch disk. Chill, wrapped in plastic wrap, until firm, at least 1 hour.
5. Cook onions in oil and butter in a 12-inch heavy skillet over medium heat, stirring occasionally, until softened and golden, about 30 minutes.
6. Preheat oven to 375°F with rack in middle.
7. Finely chop anchovies and garlic together. Stir together with tomato paste and thyme.
8. Roll out dough on a lightly floured surface with a lightly floured rolling pin into a 13-inch round.
9. Transfer to a parchment-lined large baking sheet.
10. Spread tomato-anchovy mixture over dough, leaving a 2-inch border along edge, then arrange onions on top. Fold edges of dough inward.
11. Bake until pastry is golden, 45 to 50 minutes.
12. Serve warm or at room temperature.
13. Dough can be chilled up to 3 days.Onions can be caramelized 1 day ahead and chilled.