I learned if it has the skin to start in cold water. Skinless may be lowered into simmering water. With or without white wine (dry vermouth works - I only use 10-20%). I do like 3-4 springs of parsley added. But no onion or celery to interfere with the flavor.

Lifting it out intact if you don't have a poacher is a challenge. If it threatens to break try for halves that can be placed together on the serving platter. Thin lemon slices can camouflage breaks plus fresh parsley.