Remove steak from the refrigerator 30 minutes before cooking to sit out at room temperature.
Heat your grill for approximately 10 minutes before cooking. Ensure you have a rack that provides indirect heat or that one side of the grill is not turned on. Once the grill is heated, lightly oil the grill grates. While grill is heating, combine the seasoning mix of salt, pepper, smoked paprika, garlic powder, dried minced onion and celery salt. Mix well.
Season the steak with the mix and place on the grill.
Let the steak cook for 3-4 minutes and then turn 90 degrees to allow for grill marks. Cook an additional 4 minutes. Flip to cook other side and repeat. Once marked on all sides, move the steak to the indirect heat rack. Let cook for 10-12 minutes and flip halfway through cooking.
While steak is cooking, trim the ends of the asparagus 1-2 inches and then toss in the canola oil and salt and pepper. Place on the grill and cook for 4-5 minutes.
Cook to your desired temperature. Color is not an accurate indicator of final cook temperature. Ensure final cook temperature reaches 145 F for 3 minutes. Once the desired temperature is reached, remove the steak from the grill and let rest for 10 minutes.
Serve tomahawk steak alongside asparagus.