I reheat home made frozen pizza with great success...
Microwave until thawed and cheese is just beginning to bubble at the edges.
For one small slice, this is typically 35 seconds on full power.
Then place the thawed slice on a small open grill and hold it over the flame on gas stove top. Hold it just a few inches above the flame and move it around to get the intense heat onto all parts of the slice. You should hear the sizzle. It only takes about 30 seconds. Results are very close to fresh baked.