Combine 1 T oil and potatoes, tossing to coat. Set aside.
Heat remaining oil, mustard seeds, and chiles in a large skillet over med-high. Cook 1 1/2 min or til seeds begin to pop. Reduce heat to med-low. Add ginger, garlic, and jalapeno to pan; cook 1 min, stirring constantly. Stir in salt, turmeric, and garam masala; cook 1 min, stirring constantly. Add spice mixture to potatoes; tossing to coat. Arrange potatoes in a single layer in a 13x9 inch baking pan coated with cooking spray.
Bake at 400 for 40 min or til tender and browned, stirring every 10 minutes. Stir in cilantro, mint and juice. Serve with lime wedges.