Saute onion in oil until soft, about 5 minutes. Stir in garlic; cook for 1 minute. Remove from heat; stir in lime juice, tomato, cilantro, cumin, and salt; fold in avocado. Cool to room temperature. For each roll, lay an egg roll wrapper on a work surface with corner at top. Put 1/2 cup cooled filling in a line from left to right on the center of the egg roll wrapper, leaving a 1-inch border on each side. Pull top corner over filling; fold in sides. Roll once toward bottom corner. Moisten remaining corner with water; press firm to roll. Reserve on a lightly floured sheet pan, sealed side down. Cover and refrigerate until time to fry and serve. Note: Egg rolls may be prepared to this point a few hours before final cooking. Per Serving Deep fry 2 egg rolls at 375 degrees F until golden brown, about 3 minutes. Cut on the diagonal. Serve immediately. Serving Suggestions: Serve on an appetizer plate lined with lettuce, accompanied by 1/4 cup black bean salsa, tomato or tomatillo salsa or a sweet-hot dipping sauce.
Tip: Find egg roll wrappers in the refrigerator section of the grocery store.