Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      medium        jicama -- peel and dice
   2      pounds        tomatillos -- diced
   3                    jalapenos -- seeded and minced
   1      teaspoon      cilantro -- chopped
   1      teaspoon      garlic -- chopped
   1      teaspoon      shallots -- chopped
   1                    lemon -- juice of
   1                    lime -- juice of
                        salt and black pepper -- to taste
   2      ounces        peanut oil
                        jalapeno vinegar -- to taste

Preparation:

Prepare jicama; it can be diced finely or coarsely as desired -- 1/2 inch dice is typical. Place in a large mixing bowl. To prepare tomatillos, cut ends off, remove insides and dice skins. Add to jicama in mixing bowl. Add jalapeno, cilantro, garlic, and shallots. Mix all ingredients and adjust seasoning with lemon and lime juice, salt and pepper. Add peanut oil and toss to coat mixture. Correct spiciness and heat by adding jalapeno vinegar. To make jalapeno vinegar, drop scraps and trimmings from 3 jalapenos into 1 cup white vinegar in a non-aluminum pan, bring to a boil, let cool and strain. Let sit until completely cool. Store in refrigerator. Source: Houston Gourmet Cooks 2 by Ann Criswell