In a 12-inch nonstick skillet over medium-high, heat 2 tablespoons oil until barely smoking. Add the cabbage, ¾ teaspoon salt and ½ teaspoon pepper. Cook, stirring only once or twice, until the cabbage is lightly charred, 2 to 3 minutes. Stir in the onion and cumin seeds; cook, stirring occasionally, until the vegetables are well charred, 3 to 5 minutes.

Add the remaining 2 tablespoons oil, the garlic and curry powder. Cook, stirring, until fragrant, about 30 seconds. Stir in the farro, breaking up any lumps. Distribute the mixture in an even layer and cook without stirring until you hear sizzling, about 30 seconds. Stir, distribute again in an even layer and cook until you once again hear sizzling, about another 30 seconds.

Add the tomatoes and cook, stirring occasionally, until the tomatoes are softened, 3 to 4 minutes. Off heat, stir in the lime juice. Taste and season with salt and pepper.