A good tri-tip Crock-Pot recipe is the savory chili seasoned tri-tip roast recipe provided by About.com. The recipe calls for a rub made out of various spices including chili powder, cayenne pepper, oregano and ground cumin, and an assortment of vegetables such as potatoes, onions and carrots.
To make the rub for the tri-tip, combine 2 tablespoons each of chili powder, olive oil, balsamic vinegar and Worcestershire sauce, 1/2 teaspoon each of chipotle chili powder, dried oregano and ground cumin, 1 teaspoon of onion powder and a dash of cayenne and black pepper. Rub the tri-tip roast with the ingredients, and let the meat sit overnight.
Dice 2 pounds of potatoes, 1 onion and 4 carrots, and place them into a slow cooker that's large enough to hold the tri-tip roast as well. Add 2 tablespoons of olive oil along with 1 teaspoon each of parsley and rosemary, 1/2 teaspoon each of oregano and dill, a dash of tarragon, 1 teaspoon of salt and 1/4 teaspoon of pepper. Stir the ingredients together until the vegetables are completely coated with the oil and spices. Place the tri-tip on top of the vegetables. Cover the slow cooker, and cook the meat on a low heat setting for eight to 10 hours.