In a large bowl, combine flour, ajwain, salt and ghee. Mix with fingers until the dough resembles breadcrumbs.
Add water, a little bit at a time, mix and keep adding until able to form a ball, soft but not sticky. Cover with a damp clean towel and let it rest for 40 minutes.
In a large pot over high heat, add coarse sea salt to cold water and then potatoes. When it starts boiling, set the timer for 15 minutes.
Drain the potatoes and mash them with a fork, leaving some little chunks in it; set aside.
In a large skillet over medium heat, add 1 tablespoon canola oil and 1 tablespoon ghee. When it gets hot, add cumin seeds, coriander seeds and black mustard seeds; quickly stir for 30 seconds. Add minced ginger and sauté for 30 seconds.
Add green chilies and sauté for just a few seconds before adding frozen peas. Sauté the ingredients for 2 minutes, adding lemon juice halfway through cooking. Season the mixture with garam masala, ground cumin, ground turmeric, onion powder, garlic powder and salt; stir to combine.
Add somewhat mashed potatoes and stir until everything is nicely blended, about 3 minutes. Remove from the heat to cool off.
After resting for 40 minutes, form a log with the dough and cut 6 equal pieces before forming them into balls. Cover them with a damp towel while working with one at a time so the rest don’t dry out.
Place a ball of dough on a piece of wax paper and place another piece of wax paper on top. Roll it into a circle of about 7-inch diameter – make sure it’s not too thin or too thick. Place it on a work surface and cut it in half.
Take one piece and brush water on half of the longest edge and then, brush under the other half before folding and overlapping the edges, forming a cone shape; press firmly to seal.
Stuff the cone with about 2 tablespoons of filling, pushing down gently with the back of the spoon to compress. Brush the edges of the cone with water and pinch the top closed with fingers; repeat with the other dough balls.
In a skillet over medium heat, bring the oil temperature to 320ºF. Working in batches, fry the samosas for 2 to 3 minutes, flipping them a few times. Transfer them to a baking sheet lined with paper towels while working with the others.
After they’re all done, increase the oil temperature to 380ºF. Again, working in batches, place them in the hot oil and fry them until golden, about 3 to 3 ½ minutes, flipping them occasionally.
Transfer the samosas to a clean baking sheet lined with paper towels to drain any excess fat and set aside while frying the remaining ones.