Fill 1/4 of the bottom of a couscousier with water and place on medium heat.
Place 1kg of semolina in a very large bowl.
Mix the salt into the oil and drizzle over the semolina.
Mix with a hand-held mixer until you get a cornmeal consistency.
Slowly drizzle 1-1/4 cups of water to the semolina mixture and mix with a mixer until you get a thicker cornmeal mixer. Let the mixture rest for five minutes.
Sift the semolina in a second very large bowl and set aside any lumps that you cannot breakdown.
Place the mixture in the top of the couscousier and steam for 30 minutes over medium heat.
Pour into a very large bowl and let cool. Then add 4 cups of water, stir in with a wooden spoon and let the mixture rest until all of the water has been absorbed. Sift again, removing any lumps and steam for an additional 30 minutes on medium heat. Pour into a large bowl and let cool.
Sift the mixture and place in plastic containers or use right away. You can keep the couscous in the freezer for a couple of months or in the refrigerator for three or four days.