Poaching the prawns whole with head on is great for added flavour and for those who love slurping the juice from the top of the prawn (set out a bowl for empty shells) but if you're not comfortable with that or you just want your dinner to be a little tidier, go ahead and shell the prawns first before cooking.
In a wide saucepan with high sides (see picture), heat olive oil on medium heat and saute shallot, garlic, anise seed and hot pepper flakes until onion is translucent but not browned.
Add tomato and cook until mushy, then add fennel and saute until slightly softened.
Add broth, orange zest and juice and bring to a simmer. Prepare bowls in a warm oven, bread or toast if serving and set table. Once you are ready, add prawns to broth and cook just until opaque.
Once prawns are cooked, serve them in bowls immediately with plenty of broth and garnished with fennel fronds and parsley.