Heat olive oil in a large pot over medium heat. Fry the halloumi cubes until golden on all sides, then set aside.
In the same pot, sauté the onion and garlic until fragrant.
Add the pasta, broccoli florets, and vegetable broth. Bring to a gentle boil.
Cook until pasta is al dente and liquid has mostly absorbed, about 10 to 12 minutes. Stir occasionally.
Return the halloumi to the pot, add lemon zest, and season with salt and pepper.
Sprinkle with fresh parsley before serving.