How to Make It
Place peas in 8 cups water; let stand for 2 hours. Drain. Place soaked peas, cilantro, ginger, coconut, cumin, 1/2 teaspoon salt, and 1/2 teaspoon turmeric in the bowl of a food processor; process until smooth. With processor running, slowly drizzle in 1/2 cup water until a smooth batter forms.
Heat a large nonstick skillet over medium-high heat. Add 1 tablespoon oil and mustard seeds; sauté 3 minutes or until seeds begin to sizzle and smell pungent. Add onion and serrano; sauté 3 minutes or until tender. Add mushrooms; sauté 6 minutes or until lightly browned. Add remaining 1/4 cup water, tomato, sambal, remaining 1/2 teaspoon salt, and remaining 1/2 teaspoon turmeric. Simmer 5 minutes or until thickened. Remove from pan; wipe pan clean with paper towels.
Return pan to medium-high heat; spoon 8 (1 1/2-tablespoon) mounds of batter into pan; flatten slightly to make pancakes. Pour one-third of remaining 1/2 cup canola oil around cakes. Cook 90 seconds on each side or until golden brown. Repeat procedure twice with remaining batter and oil. Top each pancake with 1 tablespoon relish.
Chauhan Ale & Masala House, Nashville, TN