I've "invented" a marinade I'm using on chicken, beef, and pork.  Tenderizes, while providing an interesting flavor.... 

 

1/3 cup Teriaki sauce (Kikoman, or whatever brand you prefer, but it must contain soy sauce)

1 tsp. Ginger (I get it in the little jars, already crushed and easy to dispense)

3 Paypaya "pills" crushed to powder  (I buy it in the Health Food stores, and crush with mortar & pestle)

 

Mix marinade in zip-lock baggie, insert meat, close and let "sit" in 'fridge for 24 hours before cooking.  I use my propane grill for most meat cooking, but I have cooked it (in the juices & marinade) in the oven for an even more intense flavor....