• Rinse the rice.

In a small sauce pot, combine the rice and ¾ cup lightly salted water. Bring to a boil, reduce to a simmer, cover, and cook until the rice is tender and the liquid is absorbed, 15 to 20 minutes. Fluff with a fork, cover, and keep warm.
While the rice cooks, prepare the rest of the meal.

• Strip the chard leaves from the stems; coarsely chop the leaves and stems, keeping them separate.
• Rinse the chickpeas.
• Finely chop, press, or grate enough garlic to measure 1 teaspoon.

In a medium sauce pot over medium heat, warm 2 tablespoons oil until hot but not smoking. Add the mirepoix and chard stems, season with salt and pepper, and cook, stirring occasionally, until the vegetables start to soften, 3 to 4 minutes. Add the chickpeas, garlic, and chickpea spice blend, season with salt and pepper, and cook, stirring occasionally, until fragrant, 2 to 3 minutes.
Add the tomatoes and vegetable broth. Bring to a boil, reduce to a simmer, and cook, stirring occasionally, until the vegetables are tender and the stew is thickened, 8 to 10 minutes. Remove from the heat. Working in batches if needed,stir in the chard leaves (they will wilt from the residual heat).
When the stew is almost done, prepare the remaining ingredients and finish the rice.

• Cut the avocado in half lengthwise. Remove the pit, scoop out the flesh, and cut the flesh into bite-size pieces.
• Coarsely chop the cilantro; set aside half for garnish.

Gently stir the avocado and half the cilantro into the rice.

Transfer the rice to individual bowls and top with the chickpea and chard stew. Dollop with the yogurt, sprinkle with the sumac and remaining cilantro, and serve.