How to Make It
Preheat broiler with oven rack in top position.
Place tomatoes in a mini food processor; pulse until pureed but not completely smooth, 4 to 5 times.
Strip chard leaves from stems; coarsely chop leaves. Cut stems into 1/2-inch pieces.
Mince 5 garlic cloves. Heat a large skillet over medium. Add 2 tablespoons oil; swirl to coat. Add onion and minced garlic; cook, stirring occasionally, 3 minutes. Add chard stem pieces; cook, stirring occasionally, until onion is tender, about 3 minutes. Add cumin, paprika, salt, and pepper; cook, stirring constantly, until heated through, about 30 seconds. Stir in chickpeas and pureed tomatoes; bring to a simmer. Add chard leaves. Reduce heat to medium-low, cover, and simmer until leaves wilt, about 5 minutes.
Cut remaining garlic clove in half. Place bread in a single layer on a baking sheet. Broil until toasted, about 1 minute. Turn bread over; brush with remaining 1 tablespoon oil. Broil until toasted, about 1 minute. Rub cut sides of halved garlic clove over oiled side of toasted bread. Place 1 toast slice on each of 4 plates; top each with about 1 cup chickpea mixture.