Wash the quinoa thoroughly in cold water 7 times. Each time rub the grains together firmly to remove the bitter coating.
Put the quinoa in a small pot with 1 1/2 cups cold water, the grated carrot, bouillon cube and salt. Bring to a boil. Once the water starts to boil, let it go for another 10 to 15 minutes and remove from the heat. Drain off whatever water remains and leave to cool.
Heat the olive oil in a medium skillet over medium-high heat. Add the onion, garlic and bay leaf and lightly fry. Remove from the heat and mix with the cooled quinoa. Add goat cheese, black olives, paprika, cumin and ground black pepper and mix well.
Preheat the oven to 400 degrees F. If you make an empanada dough, roll it out to 1/4-inch and cut out circles of about 4 inches.
Holding the circle of dough in the palm of your hand, wet the outer rim of one half of the circle with a bit of egg yolk – this will help you seal the empanada.
Place a heaping spoonful of the mixture in the middle of the circle and join the two halves of the circle.
Going from left to right, twist and fold the edge of the dough over onto itself to form the traditional repulgue (you can also complete the seal by pressing down on the edge with a fork).
Place on a baking sheet. Repeat with the remaining dough and filling. Brush the formed empanadas with egg yolk. Bake until golden brown, about 15 minutes.