Bring a large pot of water to boil, season generously with salt. Cook pasta according to package instructions.
In the meantime, heat olive oil in a large pan over medium heat, saute garlic and red chillies for 1-2 minutes until fragrant.
Add in the cherry tomatoes, cook until they begin to blister, roughly 5 minutes. Season with salt, black pepper, and oregano.
Stir in Harissa paste, saute for a minute. Then add in prawns. Cook for about 5 minutes (depending on size) until cooked through.
Add 1-2 tbsp of pasta water to loosen up the sauce and add in cooked pasta. Toss to combine.
Mix in fresh coriander leaves and serve immediately.
Notes
Different brands of would offer different blends of flavour, so do play around until you find your best pick of harissa paste. I use Belazu Smoked Chilli Harissa.
If using frozen prawns, defrost before use.
Adjust the amount of chillies accordingly to the spice level of your harissa paste and your taste preferences.