Bring the water and quinoa to a boil in a small saucepan over medium heat. Reduce the heat and simmer, covered, until quinoa is cooked and curly white germ shows, about 20 minutes.
Meanwhile, warm the olive oil in large skillet over medium heat. When the oil is shimmering, add the onion and spices, and saute until the onion has softened and the spices are very fragrant.
Stir in the pine nuts and fruit and saute for 1 to 2 minutes.
Add the cooked quinoa (all the water should have been absorbed) to the skillet. Stir in the grapefruit zest and grapefruit juice. Taste, and season with salt, pepper, to taste. Allow to sit off the heat for 10 minutes so the flavors seep into the quinoa.
Serve in lettuce cups.