Sundal refers to a stirfry in South India where theyre a common afternoon tea time snack (except, its usually served with a steaming hot steel tumbler of 'filter' coffee)
The variety in Sundals come about from the various lentils & beans used in the dish rather than the seasonings, which is a simple 'tadka' (seasoning with hot oil) of mustard. —Panfusine
Soak the Black eyed peas in plenty of water for ~ 2-3 hrs till plumped up & completely re-hydrated.
In a pan cook the beans with adequate water (i.e, submerged well) with the turmeric, till soft but not mushy. Drain & discard the excess water. Add salt, mix well & set the beans aside.
In a pan, heat the oil. when its about to smoke, add the mustard seeds and the dried red arbol chilli. When the mustard seeds begin to sputter, lower the heat & add the optional asafetida, the jalapeno & the sliced shallots.
Stir till the shallots turn limp & translucent.
Add the beans, cover & cook on low heat till all the flavors have blended (~5-8 mins).
Remove from heat, transfer into a serving dish, drizzle with the lemon juice & garnish with chopped cilantro.
(If using canned beans, omit steps 1 & 2, and add the turmeric to the pan along with the beans).