Combine split peas, garlic and broth in a large saucepan; bring to a boil. Skim off any froth. Reduce heat to low, cover and simmer for 30 minutes, stirring occasionally.
Stir in salt. Cook approximately 15 to 20 minutes more, or until peas are tender and a fairly thick puree. Remove from heat; let cool slightly, then combine the pea mixture with cilantro, cumin, pepper, lemon juice and olive oil in a food processor. Process until smooth, scraping sides of bowl occasionally. Transfer dip to a container and chill in the refrigerator for a few hours to allow the flavors to meld. Adjust seasoning, if necessary.