Peel the onions and cut in half, remove the hard root and slice as thinly as possible. Clean the garlic, chop finely and keep to one side with onions.
Place a large saucepot on the range and allow the pot to gain some heat. Add the olive oil and then immeduately add onions and garlic. Allow the onions to brown evenly, and then turn the heat down.
Add the muscovado sugar and allow the onions to cook and caramelize for 7-10 minutes. It's important that they start breaking down, sticking to the bottom of the pan so that their flavour intensifies.
Now it's time to ramp up the heat until it feels dangerous! The onions are going to start sticking a lot to the bottom of the pan leaving it brown (if you're burning to the bottom you've gone too far). When you are starting to think that you may be in trouble, deglaze the pot with red wine. It should lift nicely from the bottom of the pot and all that flavour is going to create the epic foundation of an epic broth. Turn the heat down to a gentle simmer.
Mix the onion soup powder thoroughly into your stock and add the combined mixture to your pot. This stage is all about reduction. Leave this on a gentle simmer reducing down for another 20-30 minutes. After this, add finely chopped rosemary.
Slice ciabatta into 1.5cm thick slices. Grate your cheddar cheese, chop the parsley and mix it together, you may also crack in some black pepper to this mix - it takes it to the next level. Lay out the ciabatta onto baking paper, sprinkle the cheese mix generously atop the bread and gratinate under the grill.
Chop up the fennel finely and mix into the soup just before serving. Serve the soup hot, with crunchy cheddar ciabatta croute and garnish with topside beef biltong.