The flaky, crispy, buttery crust of this tart is puff pastry (what croissants are made of). It’s topped with caramelized onions, red peppers and meaty nuggets of oil-cured black olive—all bold flavors that balance the distinct but fresh taste of the white anchovies. 

Ingredients

• 3 tablespoons unsalted butter
• 6 tbsp. extra-virgin olive oil
• 3 large yellow or white onions, peeled and thinly sliced
• 3 dried bay leaves
• 6-8 fresh thyme sprigs
• 1 teaspoon salt
• 1 large red bell pepper, thinly sliced
• 1 tbsp. apple cider vinegar
• 1 sheet all-butter puff pastry, thawed but still cool (any size from 8- by 10-in. to 10-by 15-in. will work)
• 1 1/2 tbsp. thyme leaves, plus more leaves for sprinkling on at the end
• 1 to 1 1/2 cans Patagonia Provisions Spanish White Anchovies (Lemon Olive)
• 12 to 15 oil-cured black olives, pitted

Putting It All Together

1. Put butter and oil in a large saucepan over medium heat. When butter is melted, add onions, bay leaves and thyme. Cover the onions, reduce the heat to low, and cook 30 minutes, stirring now and then, until they’re softened. Add salt and bell peppers and cook another 5 minutes.
2. Preheat the oven to 400 F with one rack in the bottom position and another in the middle.
3. Stir vinegar into onions and cook, uncovered, over medium heat, stirring often, until the juices have evaporated, another 8 to 10 minutes.
4. Poke puff pastry all over with a fork (this will keep it from puffing up like a football). Spread the onions and peppers over the pastry. Evenly space anchovies and olives (including olives from the can) over the top and sprinkle with 1 ½ tbsp. thyme leaves.
5. Bake tart on bottom rack until golden brown underneath, 20-25 minutes. Move to middle shelf another 5 minutes to brown the top. Sprinkle with more thyme and serve hot or at room temperature.