Garlic prawns with asparagus pasta in a cream sauce

Awhile back, I was at Coles when I saw these huge banana prawns. I remembered that someone told me that they were pretty tasty before and the guy over the counter just sealed the deal when he told me they had "come in fresh". At first, I was skeptical of fresh because it seems all prawns sold in Australia are frozen, but I guess he meant "freshly frozen".

Ingredients:
- Pasta for 2 people (you can use any type you like but do note the timings as different types of pasta take different amounts of time to reach al dente status)
- 10 large banana prawns, peeled and de-veined, saving the shells and head
- Asparagus, peeled and sliced
- Light soya sauce
- Chinese wine
- Dried italian herbs, or fresh parsley if you have some on hand
- Butter
- Cream
- Fish sauce (optional)
- Pepper and salt to taste

Directions:
Cook pasta as per directions on packet, then drain. Marinate prawns in pepper, soy, chinese wine and fish sauce. Pan fry the shells in oil and then add water to extract the prawn stock, discard shells and cook sliced asparagus in prawn stock then remove from heat.
Heat butter and sauté garlic with a pinch of salt until fragrant, then add prawns, when prawns are just turning pink, return asparagus and pasta to the pan and add cream and herbs. (You may choose to add some full cream fresh milk in a 1:1 ratio as a healthier option but do note this will affect the consistency of the resulting sauce, i.e. it may not coat the pasta as well). Finish with a pinch of pepper.

Modifications:
If extracting the prawn stock is too much trouble for you, you may omit and cook the asparagus directly in the cream instead. If you like a white cream sauce, omit the prawn stock and fry bacon bits before adding cream. Of course, you can purely use cream but bacon bits would definitely up the taste levels by quite a bit. If you like things spicy, add some dried chili flakes.