Place the steak in a bowl and season with Jugo Maggi, Tequila Lime seasoning, Chef Merito, and garlic powder. Toss to coat evenly and let marinate for 10 minutes.
Preheat the Blackstone to medium-high. Add the tomatoes, serranos, and whole garlic cloves directly to the griddle. Cover to steam and soften as they char, turning occasionally until blistered and tender, about 6–8 minutes.
Transfer the charred veggies to a molcajete. Mash the garlic with a pinch of salt to form a paste, then mash in the serranos. Add the tomatoes and grind to a salsa consistency. Stir in cilantro and Knorr; adjust salt to taste. Set aside.
Cook the marinated steak on the griddle until cooked through and lightly charred. Chop into bite-sized pieces.
Spread mayonnaise on the cut side of each bolillo. Toast mayo-side down on the griddle until golden and crisp.
Assemble the tortas: pile on chopped asada, then add shredded lettuce, diced onion, a drizzle of sour cream, crumbled cotija, and a spoonful of salsa molcajete.
