Add the oil to a large saucepan (for which you have a lid) and place on a medium-high heat. Once hot, add the onions and sauté for 5’, stirring occasionally, until soft. Add the vermicelli and sauté for 2’ more, stirring continuously. Add the bulgur and make sure is coated with the oil.
Stir in the tomato paste and continue cooking for another minute. Add the tomatoes along with the coriander, thyme, pour the boiling water, season with the salt and pepper and pour in the vinegar. Bring to a boil, reduce the heat to the minimum possible, cover and cook for about 10’ and until all the liquid has been absorbed.
Remove from the heat and set aside for 10’, for the bulgur to finish its cooking and to absorb large part of the liquid.
Finally, if you want a dryer Bulgur, you can optionally proceed with placing a towel in-between the pan and the lid and set aside for 10’ more.