Preparation Toast cumin in a dry small heavy skillet (preferably cast-iron) over medium heat, stirring, until deeply fragrant and dark brown (be careful not to burn). Cool, then grind to a powder in grinder. Cook chard stems, onion, garlic, 1/2 teaspoon each of cumin and salt, and 1/4 teaspoon pepper in oil in a large heavy pot over medium heat, stirring occasionally, until beginning to brown, about 12 minutes. Add tomato paste and cook, stirring, 2 minutes. Add stock, harissa, and lemon juice and simmer, covered, 30 minutes. Add chard leaves, chickpeas, and noodles with 1/2 teaspoon salt and simmer, covered, until tender, about 7 minutes. Serve soup sprinkled with remaining cumin. CooksÂ’ notes:Soup, without noodles, can be made 3 days ahead and chilled (covered once cool). Bring to a simmer and cook noodles in soup before serving.