Special equipment: a mandoline
Heat 1/2 inch of olive oil in a medium skillet. Add a tortilla and fry on both sides until crisp; drain on paper towels. Repeat with the remaining corn tortillas. Set aside.
Sprinkle the sea bass with salt and pepper, then dust with flour. Fry in the hot oil until cooked through, turning once, 5 to 7 minutes.
In a clean skillet over medium heat, cook the peppers and onions in some olive oil until softened, about 7 minutes. Add the shrimp and cook, stirring, until cooked through, a few minutes more.
Set the tostadas on plates. Spoon the bell peppers and shrimp on top. Top with a piece of fish, and then scatter with radishes, Fresno chiles and micro cilantro. Serve with lime wedges.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.