I am making some lettuce wraps, trying to imitate some yummy ones I've had out lately. The filling is finely chopped chicken breast, celery, frest mint and crushed peanuts. The sauce I tried out is garlic seasoned vinegar, a dash of olive oil, brown sugar, crushed cumin seeds and salt and pepper. The flavor of the sauce is quite good, but my question is how to make the sauce thicker. I'm not a big cook whatsoever, so I'm not exactly sure what to do. Do I simmer for a while? add something? Any suggestions? Thanks!