In a small skillet over medium heat, saute the garlic, shallots and ginger in olive oil until tender but not brown. Stir the sugar, fish sauce, water, tamarind concentrate and the lime juice together until well combined. Add to the garlic mixture and reduce over high heat by one-third or until slightly thickened. Remove from the heat and let cool. Store covered in the refrigerator for up to 2 weeks.