Report Abuse. Reheat baked pasta dishes such as lasagna in a 350 degree oven, covered. Depending on how thick the dish is, it could take from 30 to 45 minutes to heat completely.eport Abuse. Reheat baked pasta dishes such as lasagna in a 350 degree oven, covered. Depending on how thick the dish is, it could take from 30 to 45 minutes to heat completely.