In a large bowl, combine the all-purpose flour and salt.
Add the vegetable oil and warm water, mixing until a dough forms.
Knead the dough on a lightly floured surface for about 5 minutes until smooth and elastic.
Cover the dough with a damp cloth and let it rest for at least 30 minutes.
In a large skillet, heat the vegetable oil over medium heat.
Add the chopped onion and minced garlic, and sauté until the onion is translucent, about 5 minutes.
Add the ground beef or lamb and cook until browned, breaking it up with a spoon as it cooks.
Stir in the chopped green chili (if using), ground cumin, ground coriander, ground turmeric, ground black pepper, and salt. Cook for another 2-3 minutes until well combined.
Remove from heat and let the filling cool slightly.
Stir in the chopped fresh cilantro or parsley.
Divide the dough into small balls, about the size of a golf ball.
Roll each ball into a thin circle on a lightly floured surface.
Cut each circle in half to form two semi-circles.
Place a spoonful of the filling on one side of each semi-circle, then fold the dough over the filling to form a triangle. Press the edges to seal, using a little water if necessary.
Heat the vegetable oil in a deep frying pan or pot over medium-high heat until it reaches 350°F (175°C).
Fry the samboosas in batches until golden brown and crispy, about 3-4 minutes per side.
Use a slotted spoon to remove the samboosas from the oil and drain on paper towels.
Enjoy your meal!