Procedure:
Place spelt and 1 teaspoon kosher salt in a medium pot. Add water to cover by 1 1/2". Bring to a boil; reduce heat to medium-low and simmer, uncovered, until spelt is tender and water is mostly absorbed, about 1 hour (or 12-15 minutes if using semi-pearled farro). Drain; place in a large bowl.
Meanwhile, heat vegetable oil in a medium saucepan over medium heat. Add curry, mustard seeds, cardamom, and coriander; cook, stirring often, until spices are fragrant and mustard seeds begin to pop, 2-3 minutes. Stir in carrots and season with salt and pepper. Cook, stirring often, until carrots are crisp-tender, 5-6 minutes.
Stir in onion and lemon. Remove pan from heat and stir until onion is wilted, 1-2 minutes. Add vegetable mixture to bowl with spelt. Season to taste with balsamic vinegar, salt and pepper. Let cool.
Add chicken, arugula, 2 cups cilantro, and olive oil to spelt mixture; toss to combine. Transfer salad to a large platter. Garnish with cilantro sprigs.