1. To make samosas, heat oil in a skillet over medium heat. Add carrot; cook 3 minutes, stirring frequently. Add 1/2 cup onions, ginger, and garlic; cook 1 minute, stirring constantly. Add tomato paste and next 5 ingredients (through black pepper); cook 1 minute, stirring constantly. Add peas, water, and chickpeas; cook 1 minute. Remove from heat; stir in cilantro and juice. Cool.
2. Preheat oven to 400°.
3. Place 1 phyllo sheet on a large work surface (cover remaining dough to keep from drying); coat with cooking spray. Place another phyllo sheet on coated phyllo; coat with cooking spray. Fold layered sheets in half lengthwise. Spoon 2 tablespoons filling onto bottom end of rectangle, leaving a 1-inch border. Fold bottom corner over mixture, forming a triangle; keep folding back and forth into a triangle to end of phyllo strip. Tuck edges under; place seam side down on a baking sheet coated with cooking spray. Brush with melted butter. Repeat procedure with remaining 22 phyllo sheets, cooking spray, filling, and butter. Bake at 400° for 10 minutes or until crisp and golden.
4. To make raita, combine yogurt and remaining ingredients. Serve with samosas.