Recipes From The Kitchen At Bag End

This recipe appeared in the latest installment of BillThePony's "Making of Samwise" series (http://caralil.slashdom.com/sam51.html) and is courtesy of that author.

Dwarvish Peppered Pork

INGREDIENTS:
Pork fillet - 450 g (1 lb) cut into strips, Freshly ground black pepper, Butter - 25 g (1 oz), Carrots - 225 g (8 oz) peeled, cut into strips, Onion - 1 large chopped, Mushrooms - 100 g (3 oz) sliced, Irish whiskey - 3 tbsp (if you can't find a good Dwarvish brew), Soured cream - 150 ml (5 fl oz), Fresh parsley - chopped, to garnish

COOKING:
1. Liberally sprinkle the pork with black pepper. Melt the butter in a large frying pan, add the pork and carrots, stir-fry for 5 minutes.
2. Add the onions and mushrooms and cook until soft. Stir in the whiskey and soured cream and heat through, do not boil. Serve garnished with chopped parsley


I have a question concerning this recipe, thought; what is the best way to curdle cream? Leave it out, or can you add some kind of curdling agent (i.e, vinegar, lemon juice)? Can you just use sour cream instead?