In a small bowl, mix together the blackened onion powder, crushed espresso, ground coriander, salt, and black pepper to create a spice rub.

Rub the spice mixture evenly over the sirloin steak, ensuring that all sides are coated. Let it marinate for at least 30 minutes at room temperature or refrigerate for up to 4 hours for deeper flavor.

Heat the olive oil in a large skillet or Dutch oven over medium-high heat. Once hot, add the marinated sirloin steak and sear for about 3-4 minutes on each side until browned.

Remove the steak from the skillet and set aside. In the same skillet, add the diced onion and charred jalapeños. Sauté for 5-7 minutes until the onions are translucent and the jalapeños are softened.

Add the minced garlic and cook for an additional 1 minute until fragrant.

Return the sirloin to the skillet, then pour in the beef broth. Bring to a simmer, cover, and reduce the heat to low. Braise the steak for 1.5 to 2 hours until tender, flipping halfway through.

Once the steak is cooked, remove it from the skillet and let it rest for 10 minutes before slicing.

While the steak is resting, stir the pureed roasted beets and balsamic vinegar into the remaining broth mixture in the skillet. Simmer for 5 minutes, then blend until silky smooth using an immersion blender or regular blender.

To serve, slice the sirloin against the grain and plate it with a generous drizzle of the roasted beet gravy. Garnish with fresh coriander leaves.