Season Everything I'm a big fan of Gordon Ramsay and he always says you can't add a seasoned component to an unseasoned component and have the combination be magically seasoned. For example, if you are making chili, cook and season the ground beef and cook and season the vegetables, then combine.
In the early 1950s, the tri-tip cut from the bottom sirloin was often used for stews, sliced into steaks or ground. Not until Bob Shutz, a butcher in Santa Maria, experimented with this cut did it gain popularity. Now there are so many variations of the Santa Maria dry rub, it's hard to determine the original recipe but I always say variety is the spice of life The key of any good Santa Maria rub is salt, pepper and granulated garlic. What you add in addition to this foundational mixture is really up to your own personal taste buds.
I like to add dried rosemary to my Santa Maria rub. It's my favorite aromatic herb. In order to get it powdered, I use my hand-dandy NutriBullet. A Magic Bullet or any Spice Grinder or Coffee Grinder will work well also. I add whole black pepper corns along with the rosemary cause it's too difficult to grind that much pepper that finely. After a minute, I add the rest of the spices and pulse the bullet to mix them.
Generously rub your tri-tip all over with the Santa Maria dry rub. That's why they call it a rub, cause your supposed to massage or rub it into the meat for a few minutes. Don't be afraid to make a mess, that's how you know you are doing it right... lol. Two 2 pound tri-tips should just fit into a one gallon ziploc bag. Store the meat overnight so the flavors can penetrate into the meat.
Grill that slab of meat on direct heat on your outdoor grill. Tri-tip is best cooked hard and fast. Not too hard that you scorch the outside but enough that you get the perfect sear on the outside along with perfect doneness on the inside. It takes practice but tri-tip is pretty forgiving because it is so thick. A tri-tip is also thick enough to use a thermometer but it just gets in the way when you flip. I prefer not to poke my beef multiple times, letting the juices out so I prefer the touch method. If you have barbecued enough meat, you can touch it quickly with your finger or a grilling tool and instantly tell the internal temperature based on the way the meat reacts to your force. You want the tri-tip to just start firming up to get medium-rare. Too firm and it is overcooked. Too much give and it is raw in the middle.
Let your tri-tip sit for 10 minutes on the cutting board before slicing so the juices can absorb back into the meat. Cutting the beef right off the grill will result in all your delicious juices spilling out onto the cutting board.