Trim the ends and wash all the sweet potatoes. Place them in a pressure cooker, add enough water to cover, 1 tablespoon oil, and a piece of lemon (with or without juice) if using an aluminum cooker. Cook on high heat for 4 whistles, then turn off the heat. Once the cooker cools, remove the sweet potatoes.

Once the sweet potatoes are completely cool, peel and mash them. Add black salt, roasted cumin powder, chili powder, and bread crumbs. Mix well. Take a lemon-sized portion of the mashed sweet potato and shape it into a patty (tikki).

Shape all the mashed sweet potato into tikkis. Heat a cast iron or nonstick griddle and grease it with oil. Place as many tikkis as will fit on the griddle to cook.

Cook on medium heat. Drizzle oil around and on top of each tikki. Let them cook for a while, then flip with a spatula. Add more oil as needed. Cook the other side until both sides are golden brown or slightly charred. Flip again if needed. Move the tikkis from the center to the sides and bring others to the center, as the center is hotter.

Once the tikkis are cooked, turn off the heat and remove the griddle from the stove, but leave the tikkis on the griddle. Now prepare the toppings for the chaat. Make the chutneys after boiling the sweet potatoes. Prepare the other toppings now. Peel the onion. Wash the onion, tomato, cilantro, and lemon. Finely chop the onion, tomato, and cilantro. Whisk the yogurt until smooth. Place the potato sticks and crispy chana dal in a plate. Keep the spice containers ready on the kitchen counter. Place 2 to 4 tikkis on each serving plate.

Top the tikkis with green chutney, date-tamarind chutney, and yogurt. Add a little more yogurt than shown in the picture, or to your taste. Then add chopped onion, tomato, cilantro, and a squeeze of lemon juice. Sprinkle roasted cumin powder, chaat masala, chili powder, and dried mango powder.

Finally, add potato sticks and crispy chana dal. Your sweet potato tikki chaat is ready. Arrange all the tikkis on plates in the same way.