In a large pot, add coarse sea salt and bring to a boil. Add potato cubes and boil for 5 minutes. Add cauliflower florets and boil for 4 minutes.
Using a slotted spoon, transfer the veggies to a bowl and set aside. Reserve ½ cup of water.
In a large skillet over medium heat, add oil and when hot, add cumin seeds; fry for 1 ½ to 2 minutes.
And onions, sprinkle on salt and sauté until translucent, about 5 minutes.
Add green chili, tomatoes add sugar; cook for 3 minutes. Add ginger and garlic; sauté for 1 minute.
Transfer the mixture to a blender and add ¼ cup reserved vegetable water or enough to make it smooth.
Return the blended mixture back to the skillet and back on the stove.
Always on medium heat, add garam masala, cumin, coriander, turmeric, paprika, lemon zest, cayenne pepper, and black pepper; stir to blend.
Pour in chicken broth, stir before adding partially cooked potatoes and cauliflower. Stir to combine, increase the heat to high and bring the mixture to a boil.
Add green peas, stir, cover, and reduce to medium-low; cook for 8 minutes or until the veggies are tender.
Garnish with chopped cilantro and serve with naan.