In a saucepan, combine potatoes, 2 teaspoons salt, coriander, turmeric, and baking soda. Cover with water and bring to a simmer. Cook until potatoes are barely tender, about 10 to 15 minutes. Drain well.

Line a sheet pan with foil, grease with 1 tablespoon oil, and transfer potatoes onto the pan, skin side down. Let cool, cover, and refrigerate until chilled.

Preheat the oven to 475 degrees F (245 degrees C). Brush tops of potatoes with remaining tablespoon oil, sprinkle with remaining 1 teaspoon salt, and bake in the oven until browned and crusty, about 35 minutes. Let cool to just warm or room temperature.

In a small bowl, combine garlic, ginger, rice vinegar, lime juice, tamarind paste, fish sauce, salt, pepper, brown sugar, vegetable oil, and Sriracha. Whisk to combine and set aside.

In a large bowl, mix the roasted potatoes with red onions, bell peppers, jalapeno peppers, herbs, and peanuts. Pour in the dressing and mix thoroughly.

Transfer the salad to a serving platter or bowl and serve immediately.

Tamarind paste intensity may vary, so adjust according to taste preference. For a quicker version, you can skip the roasting step.