Heat oil in a pressure cooker. Throw in a tsp of mustard seeds, cumin seeds and a dash of asafoetida. Add one chopped onion, stir till golden brown. Add one chopped tomato. Stir and let cook on low to medium heat. Add a tsp turmeric powder and 2 tsps bottle masala. Mix well. Add 2 cups packed chopped spinach (if using frozen, no need to defrost ahead, just throw in frozen). Mix well, add about a large cup of rinsed half moong dal. Mix again. Add 1 tbsp freshly grated ginger, freshly squeezed juice of one large lemon, and salt to taste. Put lid on cooker and let cook for about 5 to 7 minutes. If using crock-pot, cover and simmer for 30 minutes or until done.