How to Make It
Preheat a gas grill to high (450°F to 550°F), or build a hot fire in a charcoal grill. Brush mustard greens with olive oil and sprinkle with 1/2 teaspoon salt. Working in batches, grill greens in a single layer, uncovered, until blistered and charred, about 30 seconds. Flip and grill until lightly charred and wilted, about 30 seconds. Transfer to a large baking sheet. Place lemon wedges, flesh side down, on grates, and grill, uncovered, until heated through and caramelized, about 3 minutes.
Remove any tough stems from greens. Arrange leaves on a large serving platter.
Melt coconut oil in a large skillet over medium-high. Add mustard seeds and curry leaves; cook, shaking skillet, until mustard seeds splatter and pop, about 30 seconds. Increase heat to high, and add shallots, ginger, garlic, and chiles. Cook, shaking skillet, until shallots are crisp and garlic is golden, 3 to 5 minutes. Spoon mixture over greens. Squeeze charred lemon wedges over greens. Sprinkle with garam masala, and add salt to taste.