Grind garlic with kosher salt in a mortar and pestle until it forms a paste. Whisk together garlic paste, lime juice, olive oil, cilantro, chili powder, sugar, paprika, and cayenne pepper in a bowl. Pour marinade into a resealable plastic bag, add skirt steak strips, coat thoroughly, and seal the bag. Marinate in the refrigerator for 2 hours or overnight.

Preheat oven to 300°F (150°C). Wrap tortillas tightly in aluminum foil to form a packet and warm in the oven for about 10 minutes. Keep them warm.

Heat 1 teaspoon of canola oil in a large skillet over high heat. Sauté onion and red bell pepper until browned and almost tender, about 4-5 minutes. Transfer to a plate.

Using the same skillet, heat another 1 teaspoon of canola oil over high heat. Cook half of the steak strips in the hot skillet until browned and still pink in the center, about 4-6 minutes. Transfer to the plate with onions and peppers.

Repeat with remaining oil and steak strips. Once cooked, return all ingredients (steak, onion, bell peppers) to the skillet. Add minced garlic and salt, and stir until fragrant and heated through.