1. In a frying pan over a medium flame, heat one tablespoon olive oil and sauté onion until golden brown; set aside.
2. Brown the ground beef in a large skillet with two tablespoons of olive oil, breaking up into small pieces. Season with half a package of taco seasoning, adding water according to the package directions. Cook until the water evaporates, following package instructions.
3. Add the sautéed onion to meat and mix well. Gradually add half a cup to one cup marinara sauce, being careful that the meat shouldn’t be too liquidy for wrapping.
4. Lay egg roll wrapper out on the counter. Place one and a half tablespoons meat mixture in the center of the wrapper. Fold in the sides and roll the wrapper tightly. Use a dab of water to secure the edge of the wrapper.
5. Preheat about half a cup oil for frying, depending on the size of the pot. Place egg roll carefully in heated oil for about two to four minutes, or until golden brown and crispy.
6. Drain oil by placing the egg roll on a paper towel-lined pan. Repeat with the rest of the meat. Warm the egg rolls when ready to serve.