In a large bowl, combine 3 cups all-purpose flour and 1 tsp salt. Make a well in the center, add 2 tbs vegetable oil and 0.9 cups warm water gradually. Mix until a soft but not sticky dough forms. Knead on a lightly floured surface 6–8 minutes until smooth and elastic. Place in a bowl, cover with a damp towel or plastic wrap and rest at room temperature for 30 minutes.

Beef Filling (if using beef)

Cook beef filling

Heat 2 tbs vegetable oil in a skillet over medium-high heat. Add 1 cup finely chopped onion and sauté 4–5 minutes until translucent. Add 2 minced garlic cloves and 1 chopped green chili; cook 1 minute until fragrant. Add 1 lb ground beef and increase heat to medium-high. Brown meat, breaking up lumps, 6–8 minutes until no longer pink. Stir in 1 tbs tomato paste, 0.25 cups water, 1 tsp ground cumin, 1 tsp ground coriander, 0.5 tsp black pepper and 1 tsp salt. Reduce heat to medium-low and simmer 5 minutes until mixture is fairly dry. Remove from heat and stir in 0.5 cup finely chopped cilantro. Taste and adjust salt/pepper. Let cool to room temperature before filling.

Lentil Filling (if using lentils)

Cook lentils

Place 1 cup rinsed red lentils and 2 cups water in a saucepan. Bring to a boil, then reduce to a simmer and cook 10–12 minutes until lentils are soft and most water is absorbed. If excess water remains, drain briefly. Mash lightly with a fork to a coarse paste and set aside.

Season lentils

In a skillet, heat 1 tbs vegetable oil over medium heat. Add 0.5 cup finely chopped onion and sauté 4–5 minutes until soft. Add 2 minced garlic cloves and 1 chopped green chili; cook 1 minute. Stir in cooked lentils, 1 tsp ground cumin, 0.5 tsp turmeric and 1 tsp salt. Cook together 2–3 minutes to allow flavors to meld. Remove from heat and stir in 0.25 cup chopped cilantro. Cool to room temperature before using.

Chicken Filling (if using chicken)

Cook chicken filling

Heat 2 tbs vegetable oil in a skillet over medium-high heat. Add 0.75 cup chopped onion and sauté 4–5 minutes until soft. Add 2 minced garlic cloves and 1 chopped green chili; cook 1 minute. Add 1 lb finely diced chicken thighs, increase heat to medium-high and brown, stirring, 6–8 minutes until cooked through. Stir in 1 tsp ground cumin, 1 tsp ground coriander, 0.5 tsp black pepper and 1 tsp salt. Reduce heat to medium and cook 2–3 minutes more to eliminate excess moisture. Remove from heat and fold in 0.5 cup chopped cilantro. Cool to room temperature before filling.

Assemble Sambusas

Divide and roll dough

After dough has rested, divide it into 12 equal pieces (about 2 oz / 56 g each). Keep unused pieces covered. Roll each piece into a ball, then flatten into a 5–6 inch round about 1.5–2 mm thick on a lightly floured surface.

Fill and fold

Place 1.5–2 tbs of chosen cooled filling (beef, lentil, or chicken) on one half of the round, about 1 inch from the edge. Brush the opposite edge with the sealing paste made by mixing 0.25 cup flour and 2 tbs water to a thick paste (or use a little water). Fold the dough over the filling into a half-moon and press edges to seal. Optionally fold into a triangular samosa shape by folding the sealed half into thirds, sealing each seam with the paste. Ensure seams are well sealed to prevent filling leakage.

Frying

Heat oil

Pour vegetable oil into a deep pot or heavy skillet to a depth of 2–3 inches (about 1 liter). Heat the oil to 350°F (175°C). If you don't have a thermometer, test by dropping a small scrap of dough — it should sizzle and rise steadily.

Fry sambusas

Carefully add 3–4 sambusas to the hot oil without overcrowding. Fry 2–3 minutes per side until golden brown and crisp, turning gently with a slotted spoon. Adjust heat as needed to maintain 325–350°F and prevent burning. Remove to a paper towel-lined tray to drain. Repeat with remaining sambusas.

Serve

Serve warm with lemon wedges and yogurt or chutney. Sambusas are best eaten the same day while crisp.