Thaw scallops and pat dry.
Add scallops to a bowl and gently toss in olive oil and taco seasoning.
Preheat grill or skillet to medium- high heat. If using a skillet, heat olive oil in the skillet.
Add scallops to grill or skillet and cook for 2-3 minutes per side. Once cooked, set aside on a plate.
To make the tostadas, heat olive oil in a skillet over medium-high heat and fry the corn tortillas for 5 minutes, flipping halfway through. Set aside on a plate and pat oil out with a paper towel.
Once cooled, spread guacamole over the tostadas. Top with scallops, cotija cheese, freshly chopped cilantro, and a slice of lime.
Serve immediately and enjoy!