Heat the oven to about 400 degrees. Close enough is fine.
Line a baking sheet with parchment paper or foil.
Cut the broccoli into medium pieces and spread them on the pan.
Drizzle the broccoli with half the olive oil. Add salt and pepper. Toss it around a bit.
Put the pan in the oven and roast the broccoli for about 10 minutes.
While that’s going, place the salmon on the same pan or a second pan.
Drizzle the salmon with the remaining olive oil. Add salt, pepper, and garlic if using.
Slide the salmon into the oven with the broccoli.
Bake everything for another 12 to 15 minutes, until the salmon flakes easily and the broccoli has dark edges.
Take it out. Add lemon if you want. Eat while it’s hot.