Heat oil in large Dutch oven on medium. Add garlic and zest and cook, stirring, 1 minute. Add red pepper and fennel and cook, stirring, 2 more minutes.
Add tomato puree, 4 cups water, and 1 teaspoon salt. Cover and bring to a boil; add kale and simmer 4 minutes.
Add chickpeas and simmer until heated through, about 2 minutes more. Serve with Pecorino and lemon wedges if desired.