Remove the skirt steak from the packaging and trim any fat and sinew off. Place the skirt steak in a 1-gallon zip-seal bag or alternatively in a large bowl.
Combine the garlic, red onion, jalapeño, lime zest and lime juice, cilantro, cumin, black pepper, canola oil in a blender and puree. Pour over the skirt steak, making sure all areas of the steak are completely covered. Place back into the refrigerator and let marinate for 2-4 hours.
Once the skirt steak has been marinated, preheat grill to medium high. Season the skirt steak with 4 tsp kosher salt and place over direct heat and let the skirt steak cook for 4-5 minutes on each side. Cook to your desired temperature. Color is not an accurate indicator of final temperature. Ensure final cook temperature reaches 145 F for 3 minutes. Remove and let rest for 5 minutes.
Transfer the skirt steak to a cutting board and slice thinly. Place on a serving platter and serve with tortillas, roasted salsa, radish, red onion, lime wedges, cilantro leaves and queso fresco.