Heat 2 tbsp oil or ghee in a pan over medium heat.
Add 2 tsp whole cumin seeds and let them sizzle for a few seconds until fragrant.
Add the cubed potatoes and fry until they develop a slight char on the edges and are lightly golden.
Remove the potatoes from the pan and set aside.
In the same pan, add 1 tbsp ghee.
Add the chopped onion and sauté until soft and golden.
Stir in tomatoes, green chilli, and all the spices — turmeric, red chilli, coriander, cumin, and salt.
Cook for 3–4 minutes until the tomatoes soften and the mixture becomes glossy and aromatic.
Add ¼ cup water and mix to create a smooth masala.
Return the fried potatoes to the pan and toss to coat them well.
Add the boiled peas, stir, and cover the pan. Let it simmer on low heat for 10–12 minutes, until the potatoes are tender and everything comes together beautifully.
Crush the fenugreek leaves between your palms and sprinkle them into the curry.
Add garam masala, give it one final stir, and turn off the heat.
Serve hot with roti, paratha, or basmati rice.