Ina large saucepan, bring water, salt and quinoa to boil. Reduce heat to medium-low, cover and cook until quinoa is tender and water has been absorbed, about 15 minutes, set aside.
Heat the olive oil in a large skillet over medium heat. Add the pine nuts or sunflower nuts and cook until lightly toasted, about 2 minutes. Add the garlic and cook just until it starts to brown, about 2 minutes. Remove garlic and discard. Stir in the cooked quinoa and spinach. Heat until the spinach wilts. Stir in the lemon juice and all but a pinch of the cheese. Stir until the cheese has melted. Serve sprinkled with the remaining cheese.