Place 625 g flour into a mixing bowl along with 54 g vegetable oil and 5.8 g salt. Rub the oil through the flour using your fingertips until the texture turns crumbly. Pour in just enough water to bring the ingredients together into a soft, smooth dough, then set aside.
Heat 67.5 g vegetable oil in a wok or deep skillet until it begins to smoke lightly, then lower the heat. Add 1 tablespoon chopped onion and fry for roughly 5 minutes until browned and caramelized. Stir in the ginger-garlic paste and cook until the oil begins to separate from the aromatics. Pour in the ground spice mix and fry for another 5 minutes.
Add 150 g diced potato, 150 g chopped cauliflower, and 50 g shelled peas to the spiced oil, seasoning with salt to taste. Sauté until the vegetables are thoroughly cooked and tender. Mix in 50 g shelled peanuts, take the pan off the heat, and allow the filling to cool down completely.
Divide the rested dough into 12 equal portions. Flatten each piece and roll it out into a 5-cm (2-inch) round, then slice across the middle into two semicircles. Place 1 tablespoon of the vegetable filling onto each half-moon, fold the pastry over to enclose it, and firmly pinch the edges together to form a tight seal.
Heat vegetable oil for deep-frying in a deep, heavy pot to 180°C (350°F), or until a bread cube browns in 30 seconds. Carefully lower the samosas into the oil and fry in batches until crisp and evenly golden brown. Lift them out using a slotted spoon and let them drain on paper towels.
Steep a tiny pinch (0.1 g per 2 g turmeric) in 2 tbsp warm water; use to match the rich golden hue. Contributes an aristocratic, honeyed floral flavour rather than earthy bitterness.
Use 50% of the weight and stir in near the end of cooking. Adds warmth and depth since it contains ground coriander, but introduces stronger spices like clove and cinnamon.
Use 80% of the weight, finely shredded and browned slowly with a pinch of asafoetida. Replicates the bulk and natural sweetness in gravies without allium.