i sprout my eggplant seeds in a plastic gallon jug. I cut it almost all around but leave enough so that i can put the top back on. Take the old eggplant and put it in a blender and whiz it up and pour the contents on potting soil in the plastic jug. Tape the top back on and set it outside. Wait for the sprouts to fill the jug then cut it open and take it out and put it in water to separate the seedlings then plant them in soft soil about five inches apart. Prune and transplant as they get bigger. You will get eggplant not like the hybrid parent. Some very interesting.
If you don''t want to go through this process just buy a packet of hybrid seed and plant according to directions.