Place a large soup pot over medium-high heat and add in the olive oil. Once oil heats, add in the chicken sausage, crumble with a wooden spoon and cook for 5 minutes or until the sausage starts to brown on the edges. Add in the red pepper flakes, garlic, onions and celery, season with salt and pepper and let cook until onions are translucent, about 3 minutes.

Add in the broth and bring to a boil. Once boiling, let cook for 5 minutes and then add in the zucchini noodles and cook for another 5 minutes or until cooked to your preference.

Meanwhile, add all of the ingredients for the pesto into a food processor and pulse for 30 seconds. The pesto shouldn’t be like a normal pesto, it should be thicker and not as creamy.

When soup is done cooking, add in the pesto and stir to combine. Serve immediately.