Prepare the chicken: In a medium bowl, combine 1/2 tablespoon oil, garlic, ginger, and cumin. Add the turmeric, season lightly with salt and pepper, and whisk to blend. Lightly pound the chicken pieces to even them out, then turn to coat in the oil-spice mixture. Let stand for 20 to 30 minutes.

Meanwhile, cook the zucchini: Heat the remaining tablespoon of oil in a medium skillet over medium-high heat until hot. Add the zucchini pieces and cook, stirring often until crisp-tender, about 4 minutes. Remove from heat.

Heat a heavy large skillet over medium high heat until hot. Add the chicken, smooth side down and cook until golden brown underneath, about 4 minutes. Flip with a spatula, reduce the heat to medium, and cook about 4 minutes more, until just cooked through. Transfer the chicken to a plate and tent with foil. Do not clean the pan.

Drain the cauliflower well in a colander. To the same large skillet the chicken was cooked in, add the oil, onion, and water; cook, stirring over medium heat until softened, about 3 minutes. Add the garlic, ginger, cumin, and turmeric, and cook, stirring for 3 minutes more. Add the drained cauliflower and garbanzo beans and cook over medium heat until hot, about 5 minutes. Stir in the cilantro and season with salt and pepper.

Divide the cauliflower rice among 4 large soup bowls. Slice the chicken against the grain and arrange on top of the cauliflower, along with the grapes and cooked zucchini. Serve warm.