Mix the seasonings for the chicken in the bottom of a bowl and add enough olive oil to form a paste, a quarter cup or less.
Dredge the chicken thighs through the paste and use your fingers to coat the meat. Cover and refrigerate. Let the meat marinate for at least an hour. Bring to room temperature before cooking.
While the chicken is warming up, make the relish by pulsing the salt and garlic together in a food processor.
Add the chilis, cilantro, mint and olives. Pulse and use a spatula to clear the sides as needed. You want the relish to be chunky rather than pureed.
Transfer to a bowl and add the most of the vinegar and olive oil, mixing and adding more vinegar or oil until the consistency seems right to you. Not too dry, but not loose either. Finish with a squeeze of lemon juice. Set aside.
Cook the chicken however you like. I grilled mine on a grill pan that had been sprayed with a little olive oil, but if you'd rather pan fry or bake it, that's fine.