Preheat the oven to 425°F. Using a paper towel, pat the chicken thighs dry. Season generously on all sides with salt and pepper.

In a 12-inch cast-iron or other ovenproof skillet, heat 1 tablespoon of the oil over medium heat. Add the chicken skin-side down and cook until the skin looks golden and crisp, and releases easily from the pan, 6 to 8 minutes. If the chicken skin sticks when you try to flip it, it just needs more time to crisp. Flip and cook until golden, 4 to 5 minutes. Transfer the chicken to a plate.

Add the remaining 2 tablespoons oil and the shallots to the hot pan and cook until the shallots are slightly softened, about 2 minutes. Add the couscous and continue cooking, stirring occasionally, until it’s fragrant and turning a toasty brown color, 4 to 5 minutes. Add the water, garlic, chicken bouillon, and a hefty pinch of salt. Arrange the chicken thighs on top, crispy skin-side up. Increase the heat to medium-high and bring to a simmer. Remove the pan from the heat.

Carefully cover the hot pan with aluminum foil, pinching around the sides to create a tight seal. Transfer to the oven and bake until most of the liquid has been absorbed, 30 to 35 minutes.

Remove the foil from the chicken and bake for another 5 minutes. Preheat the broiler. Place the oven rack about 4 inches from the heating element. Broil until the chicken skin becomes crispy, 2 to 3 minutes. Remove from the oven. Fish out the softened garlic cloves and crush them on top of the crispy chicken thighs.