1. To prepare chutney, combine first 9 ingredients in a blender; process until smooth. Set aside.
2. To prepare samosas, combine potatoes, lentils, mint, curry powder, 1 teaspoon butter, 1/4 teaspoon salt, and cumin. Gently fold in peas.
3. Working with 1 egg roll wrapper at a time (cover remaining wrappers to prevent drying), cut down middle to form 2 long rectangles. Moisten edges of wrapper with egg. Spoon 1 tablespoon potato mixture near bottom edge of wrapper. Fold up from 1 corner to the opposite outer edge of the wrapper, making a triangle. Fold over to opposite side again as if folding up a flag. Repeat fold to opposite side to form a triangle. Repeat with remaining wrappers and filling.
4. Heat a large cast-iron skillet over medium-high heat. Coat pan with cooking spray. Lightly coat samosas with cooking spray. Add samosas to pan, and cook 1 minute on each side. Drain on paper towels. Serve with chutney.