Bring a large pot of salted water to boil for the pasta.
Cut the chicken breast in to bite sized pieces and add to a bowl. Sprinkle with the plain flour, garlic granules, dried parsley and a pinch of salt and pepper. Toss well to coat the chicken in the seasoning.
To make the garlic breadcrumbs, warm the oil in a non-stick pan over medium heat and add the breadcrumbs. Toast them by mixing gently over the heat until they turn golden brown. Stir in the garlic granules, dried parsley and a pinch of salt then transfer to a bowl to cool.
In the same non stick pan used for the breadcrumbs, melt the butter and add the diced chicken and cook until beginning to brown. Add the onions for 2-3 minutes until beginning to soften then add the garlic for 1-2 minutes until fragrant. Pour over the stock and simmer for about 10 minutes while the pasta is cooking.
Cook the pasta according to packet instructions until just al dente.
Chop the broccoli into bite sized florets and add to the water with the pasta for the final 2 minutes of cooking. Reserve a cup of cooking water before draining.
Stir the cream into the pan with the chicken then add the drained pasta and broccoli with about a tablespoon of pasta cooking water. Stir well until everything is combined and creamy. Add more pasta water as necessary until the sauce is your desired consistency. Season with salt and black pepper to taste.
Stir in some fresh chopped parsley and serve topped with a generous sprinkle of garlic breadcrumbs.