Hey Al,
Great thread. I've never heard of using the egg whites in a mason jar for consume. Definitely looking forward to playing around with that trick. Also, at what temp are you infusing your oils? Do you use a different temperature for an herb oil that has chlorophyll to preserve the color, or is it pretty standard across the board?
As for me, I've had great results with anything custard based. Lately I've been using Ziploc bags instead of the chamber sealer when cooking my proteins because I find that the vacuum pressure as others have mentioned will slightly change the texture but also intensify flavors. Sometimes you want that intense herb flavor to become a part of the protein, other times it's necessary to keep it subtle.
Like you, one of my favorite things to cook sous vide is a rack of lamb. My lamb racks come vacuum packed from my meat purveyor so I just drop them into a 56C bath for one hour, just to do a pre-cook. At the end of the hour, I'll carefully cut open the bag (no shocking in ice), pour any juices into a separate container and then cool the lamb. The fat cap is seared using some infused roasted garlic oil. Using the rendered fat from the lamb, I make a basic pan sauce using shallots, onions, white wine for deglazing and a roasted chicken stock that has been reduced by about 2/3. The lamb "juice" is added to the pan sauce which is reduced until it reaches a slight nape consistency. The sauce is skimmed and strained.
The lamb rack is cut into four bone servings and placed in an individual Ziploc bag along with five cloves of roasted garlic, a small pinch of fried rosemary and a few batons of slab bacon. The bag is dipped into a water bath, a 4 oz ladle of the pan sauce is added, allowing the bag to drop under the water line, at which point the bag sealed. In my experience, if all the ingredients were chamber sealed together, the pressure would intensify the garlic and rosemary flavors, making them over bearing. I've also tried making the sauce with lamb stock, but it becomes too strong and one dimensional IMO. The lamb flavor infuses nicely into the chicken stock yielding, at least for my taste, a more balanced sauce.
For service we place a few of the bags in a 55C bath and let cook for at least 30 min to 1 hour, although the texture and flavor will become better up to 4 hours of cooking, giving us a wide window of time to sell the lamb. On pickup, the contents of the bag are poured into a hot sauce pan (minus the lamb) and reduced a la minute, finishing with a little swirl of butter. The exterior of the rack is re-crisped with a MAP gas torch.
RE Game Meats: I've had good luck with bone in Elk chops but that's about it. Given, the Elk was from a farm in New Zealand, not killed in the wild. But then again, most chefs aren't serving "true" wild game in their restaurants. When cooking rabbit I tend to go old school French with good results; never tried cooking it sous vide.