Tri-tip is a cut of beef. Costco has really good tri tip. They come two to a package.
3/4 cup soy sauce (I use low sodium)
1/4 cup sugar
1/4 cup pineapple juice
2 tsp. peeled, grated fresh ginger root
1 to 2 garlic cloves, minced (I like lots of garlic)
This is enough marinade for one tri-tip roast. Slice the tri-tip thinly (about 1/4 inch) along the grain of the meat. Put in a gallon-size ziploc bag. Pour the marinade over the meat. Make sure all of the meat is covered. Let marinate at least 24 hours. Grill.
We love this. It is really good cold the next day, too.