Nice looking cooked Tri-Tip, I'm sure it was super tasty...
Personally I buy just the straight ol raw Tri-Tip when it goes on sale, under $3.00 lb. Usually get 2 or 3.
You can get real extravagant with marinades and rubs, but really Tri-Tip doesn't need a whole lot of seasoning and prep if it is just cooked properly.
Sometimes just season with McCormicks Steak Seasoning and throw on the grill. I have tried marinades of various concoctions for up to 24 hours too. A simple marinade of (olive oil, garlic, ground fresh pepper corns, salt, *use McCormicks works fine too press the seasoning into the meat) for about 1-2 hours will get the desired results, (You really want to taste the meat enhanced with just bit of seasoning and dose of smoke), the taste is amazing if done right.
Here on SMF I see people smoking Tri-Tip, but I sort of believe this meat is so juicy tender when cooked properly over a grill I have a hard time justifying smoking a great cut of meat like Tri-Tip. I use my weber kettle, two zone fire setup, coals on one side (I have a rack that I use to keep the briquettes completely on one side). The briquette rack is about 4 " high and I pile up an even layer of coals almost 4" about 1 1/2 starter Sleeves. I want the fire real hot to get a good crusty sear in 6-8 minutes. After both sides are seared sealing in the juices, I move the tri-tip over to the cool side and finish using indirect heat. I have tried different wood, oak seems to give that authentic flavor. Hickory is a bit strong, and mesquite can actually be bitter. I now have some almond and will be trying that next. I do use a digital remote probe to monitor the internal temp of the meat, and remove the meat completely around 132-135, I like to put in foil covered pan and put in Microwave 10 minutes (not running) to let the juices settle, until ready to cut for serving. Always remember to cut across the grain or you will have a tough time chewing.
I try to keep braising liquid from a small pork roast,(fat removed and reduced 50 %) in the fridge for meat sauces. That braising liquid combined with the tri-tip juices while sitting and some red wine, makes a great meat sauce. Be sure and save some of this sauce and use it for sandwiches the next day. Yum...
sides usually vary with what is available:
If you want to kick up the seasoning a bit here is a recipe I use, combine and put in fridge 3-4 hrs.
2 teaspoons salt
2 teaspoons black pepper fresh ground
2 teaspoon garlic powder
1/2 tablespoon paprika
1 teaspoon onion powder
1/4 teaspoon cayenne pepper
1 teaspoon dried rosemary
3-4 cloves crushed garlic