In a large bowl, whisk together 3 cups all-purpose flour and 1 tsp salt. Add the cold cubed butter and 2 tbs shortening. Using a pastry cutter or your fingertips, cut the fats into the flour until mixture resembles coarse crumbs with some pea-sized pieces.

Add water and form

Sprinkle 5 tbsp ice water over the flour mixture, 1 tablespoon at a time, tossing gently with a fork until dough just comes together. Do not overwork. Gather the dough into a ball, divide into 8 equal portions (for 8 pastéis), flatten each into a disk, wrap in plastic, and chill in refrigerator for at least 30 minutes.

Prepare egg wash

Beat 1 whole egg with 1 tbsp milk in a small bowl and set aside for brushing before baking or after filling and before frying.

Filling

Prep potatoes (if using)

If using diced potato, place in a small pot of cold salted water, bring to a simmer and cook 6–8 minutes until just tender. Drain and set aside. This ensures potatoes are cooked through inside the pastel.

Sauté aromatics and vegetables

Heat 1 tbsp olive oil (or reserved tuna oil) in a skillet over medium heat. Add the finely chopped onion and sauté 4–5 minutes until translucent. Add the minced garlic and sauté 30–45 seconds until fragrant. Add the diced red bell pepper and cook 2–3 minutes until softened.

Build the filling

Stir in 2 tbsp tomato paste and 1/2 cup diced tomatoes, cook 2 minutes to remove raw tomato taste. Add 1/2 cup peas, cooked diced potato (if using), 2 cups flaked drained tuna, 1 tsp dried oregano, 1/2 tsp ground cumin (optional), 1 tsp salt, 1/2 tsp black pepper and 1/2 tsp sugar (optional). Mix gently and cook 2–3 minutes until heated through and combined.

Finish the filling

Remove skillet from heat. Stir in 2 tbsp chopped fresh parsley and 1 tbsp lemon juice. Taste and adjust seasoning. Let the filling cool for 10–15 minutes so it’s easier to handle and won’t leak through pastry.

Assembly and Cooking

Roll out dough

Lightly flour a work surface with the 1/4 cup flour. Working with one chilled dough disk at a time, roll it out to about 1/8-inch thickness into roughly 6–7 inch circles (for individual pastéis). Keep unused dough chilled.

Fill and seal

Place about 3 tablespoons of the cooled tuna filling onto the center of each dough circle, leaving a 1/2-inch border. Brush the border with egg wash. Fold the dough over to form a half-moon and press the edges together. Use a fork to crimp and seal the edges securely, or fold the edge decoratively to ensure no filling escapes.

Cook: Frying method (traditional)

Pour enough oil into a deep skillet to reach about 1/2 inch depth and heat to 350°F (175°C). Fry pastéis in batches, seam-side down first, for 2–3 minutes per side until golden brown and crisp. Transfer to a plate lined with paper towels to drain.

Cook: Baking method (lighter)

Preheat oven to 400°F (200°C). Place assembled pastéis on a parchment-lined baking sheet, brush tops with egg wash, and make a small vent slit in each. Bake 18–22 minutes until golden and puffed. If desired, turn on broiler for the last 1–2 minutes to deepen color, watching carefully.

Serve

Let cooked pastéis rest 3–5 minutes, then serve warm with a squeeze of lemon or a dipping sauce such as hot sauce, chimichurri, or a simple garlic aioli.