Preheat your oven to 400°F and line a baking sheet with parchment paper.
In a bowl, toss the broccoli florets with 1.5 teaspoons of olive oil, salt, and pepper.
Spread the broccoli on the baking sheet and roast for 15-20 minutes until the edges are browned and tender.
While the broccoli roasts, ensure your quinoa is cooked and kept warm.
On a small plate, combine the dried oregano, dried thyme, lemon zest, and a pinch of salt.
Pat the tuna steak dry with a paper towel and press both sides firmly into the herb mixture to create an even crust.
Heat the remaining 1 teaspoon of olive oil in a non-stick skillet over medium-high heat.
Sear the tuna steak for 1.5 to 2 minutes per side for a medium-rare center, or longer if you prefer it more well-done.
Slice the tuna against the grain and serve immediately over the quinoa with the roasted broccoli on the side.