1. Place first 7 ingredients in a food processor; pulse 4 times or until chopped.
2. Heat a large nonstick skillet over medium heat. Coat pan with cooking spray. Add bell pepper and 1/4 cup onion; cook 4 minutes, stirring frequently. Add serrano; cook 1 minute. Place bell pepper mixture in a large bowl. Weigh or lightly spoon flours into dry measuring cups; level with a knife. Add flours, salt, cumin, and fennel seeds to bell pepper mixture. Stir in 1 cup water, and let stand 3 minutes.
3. Heat 1/2 teaspoon oil in pan over medium heat. Pour 1/3 cup batter per pancake into pan; spread batter into 2 (5-inch) circles. Cook 2 minutes or until tops are covered with bubbles and edges look cooked. Flip pancakes; cook 2 minutes or until bottoms are lightly browned. Repeat procedure twice with remaining oil and batter. Serve with chutney and yogurt.