Step 1

Place chickpeas in a medium saucepan and pour in water to cover by 2"; season with salt. Bring to a boil, then reduce heat to medium-low and simmer, stirring occasionally and adding more water as needed to keep covered, until tender and very creamy, 45–60 minutes. Drain.

Step 2

Meanwhile, combine potatoes and turmeric in another medium saucepan and pour in water to cover by 2"; season with salt. Bring to a boil, then reduce heat to medium-low and simmer, stirring occasionally, until potatoes are tender, 8–10 minutes. Drain.

Step 3

Purée tamarind concentrate, date syrup, ginger, 2 Tbsp. chaat masala, 1 tsp. cumin, 1 tsp. red chili powder, and ¼ cup cold water in a blender until smooth. Season tamarind chutney with salt.

Step 4

Mix yogurt, 2 Tbsp. chaat masala, remaining 2 tsp. cumin, and remaining 2 tsp. red chili powder in a small bowl to combine; season with salt.

Step 5

Pour oil into a large pot to come 3" up sides and fit with thermometer. Heat over medium until thermometer registers 350°. Working in batches, slip 6–10 puris into oil and fry, turning with a slotted spoon, until golden and puffed, about 30 seconds. Transfer puris to a paper-towel-lined baking sheet.

Step 6

Break open puri on one side and fill each one with 1 Tbsp. chickpeas and 1 Tbsp. potatoes. Transfer to a platter; drizzle with spiced yogurt, tamarind chutney, and Scallion Chutney. Scatter red onion, cilantro, mint, and sev over and sprinkle with more chaat masala.