My method for seed starting is to fill the bottom half of the container with new potting soil and the top half with peat moss based seed starting soil.
Redux - because the first planting of broccoli seeds because burned up during our 2 week relocation to the surface of the sun. Broccoli grows in 75 degree days and 50 degree nights. If temperatures sustain much hotter or colder, you can say bye bye.
Make a hole in the center of each cell. Broccoli seeds are planted one-fourth to one-half inch deep.
Drop a couple of seeds into each hole and cover with soil. Fill the tray under the seed starting container with water. A drop of seaweed fertilizer can be added to a gallon of water to get the soil ready to receive the roots.
Seeds need soil contact points so press the soil down onto the seeds.
This step is not necessary but I do it. Sprinkle the top with vermiculite.
Spray the top of the soil with mister. I'm putting on diluted fungicide to reduce the possibility of damping off disease.
Broccoli seeds will not germinate in the weather we are currently having - it's still too hot. These will come into the air conditioned house for the ten days they need to pop up.