Cut the shallot in half lengthways, peel it and then dice it as finely as you can.
Peel the garlic cloves and slice them as thinly as you can.
Heat a small-medium (18cm) saucepan over a medium heat, and when it is hot, add the olive oil.
Add the chilli flakes, dried oregano, sliced garlic, and diced shallot, then saute for 2-3 minutes. If the shallots and garlic begin to brown, turn down the heat.
Pour in the vegetable stock and tomato passata, add the sugar and stir.
Have a taste and add the salt; you may need more or less depending on your stock.
Simmer the soup base for 10 minutes.
Add in the tortellini and cook as per the packet instructions (usually 2-3 minutes).