To Remove Excess Saltiness, Blanch The Pork Dice By Simmering Them In 2 Cups Of Water For 5 Minutes, Drain On Paper Towels And Pat Dry. In A Heavy 10" To 12" Skillet, Melt 1 Tablespoon Of The Butter Over Moderate Heat, And In It Brown The Pork Dice, Stirring Them Or Shaking The Pan Frequently, Until They Are Crisp And Golden. Remove Them With A Slotted Spoon And Set Them Aside To Drain On Paper Towels. Pour Off Almost All The Rendered Fat From The Skillet Into A Small Bowl, Leaving Just Enough In The Skillet To Make A Thin Film About 1/16" Deep On The Bottom. Set The Bowl Of Fat And Skillet Aside. In Another Heavy 10" To 12" Skillet, Melt 4 Tablespoons Of Butter Over Moderate Heat. When The Foam Subsides, Add The Sliced Onions And Cook Them Over Low Heat, Turning Them Frequently With A Wide Metal Spatula, For 20 To 30 Minutes, Or Until They Become Limp And Lightly Colored. While The Onions Are Cooking, Heat The Fat In The First Skillet Of Moderate Heat Until It Almost Smokes. Dry The Beef With Paper Towels, Then Brown It In The Hot Oil 4 Or 5 Chunks At A Time To Avoid Crowding The Skillet, Adding More Pork Fat As Needed. When The Chunks Are A Rich Brown On All Sides, Remove Them With Kitchen Tongs To A Dutch Oven Or A Heavy Flameproof Casserole About 9" To 10" In Diameter And At Least 3" Deep. Bury The Bouquet Garni In The Meat. Preheat The Oven To 350 Degrees. After All The Meat Is Browned, Remove The Skillet From The Heat And Stir The Flour Into The Fat Remaining In It. If The Mixture Seems Dry, Add A Little More Pork Fat (Or Vegetable Oil). Return To Very Low Heat And Cook, Stirring Constantly, Until The Roux Is Amber Color: Be Careful It Doesn'T Burn. Remove From Heat, Pour In The Beer And Beef Stock, And Beat Vigorously With A Wire Whisk Until The Roux And Liquid Are Blended. Bring To A Boil Over Moderate Heat, Whisking Constantly As The Sauce Thickens. Boil For 1 Minute, Then Mix In The Sugar, Vinegar, Garlic And Thyme, And Simmer Over Low Heat For 2 Or 3 Minutes. Taste The Sauce And Season It With Salt And Pepper If Needed. When The Onions Are Done, Add Them To The Casserole, And Pour The Sauce Over The Onions And Meat, Stirring The Mixture Gently. The Sauce Should Nearly Cover The Meat; Add More Beer If Needed. Bring The Casserole To A Boil On Top Of The Stove, Cover It Tightly And Place It In The Lower Third Of The Oven. Cook, Regulating The Oven Heat So That The Meat Simmers Slowly For 1-1/2 To 2 Hours, Or Until The Meat Is Tender When Pierced With The Tip Of A Sharp Knife. Before Serving, Let The Carbonades Cool For A Few Minutes. Then Skim Off The Surface Fat, Discard The Bouquet Garni And Taste The Sauce For Seasoning. Sprinkle The Carbonades With The Crisp Pork Bits And Garnish With Chopped Parsley.