What do you think of this process for making chicken and steak fajitas almost simultaneously?
I made a marinade of lime juice, olive oil and seasonings.
I added half to each of two freezer bags.
I added an angus strip steak to one and one boneless, skinless chicken breast to the other.
I want to cook the chicken to 143 degrees and the steak to 134 degrees.
I add the chicken to the water bath and cook for 1 1/2 hours. I then lower the temperature to 134 degrees.
After that comes to temp, I add the steak and cook for another 1 1/4 hours. (The steak has been sitting in the frig until 30 minutes before going into the sous vide.)
Dinner is close, otherwise I would let the steak go 1 1/2 - 2 hours.
Pull everything out, sear and slice into strips and serve. I have read that the bacteria has been killed on the chicken if it was cooked to 140 degrees for 9 1/2 minutes. So I assume it is safe to eat after 1 1/2 hours and still safe if I leave it in the water bath while the steak cooks.
With the whole cook less than 4 hours, it seems like my sous vide would not act as an incubator for bacteria. Thanks for any comments.
You don’t mention what thickness the meats are, so no-one can advise on whether those times are sufficient to ensure that everything’s cooked. 
From an order of operations, yep, you have it nailed down - cook the higher temp meat first, then let it stay in the bath while the more rare meat cooks (provided you’re above 130F) - the “tipping point” where pathogens start dying off is actually 127F, but we use 130F as a guideline to make sure no-one gets sick.
Lots of thickness guides for the types of meats on Baldwin’s site: http://www.douglasbaldwin.com/sous-vide.html
I think Laurie knows what she’s doing. Just don’t ever let the chicken and meat marinate too long, as in all day or worse, overnight.
Replace the salt in your marinade with soy sauce to enhance flavours.
I would go from fridge to bath with the steak, too. Half an hour sitting on the bench is of no benefit to anyone, except bacteria. Really, the idea that steak should be at room temp for cooking really needs to die.