First, prepare the shrimp by peeling, deveining, removing the stems, and either butterflying them or slicing completely in half. Place these in a bowl along with ¼ cup lime and a pinch of salt.

Let the acid from the lime cook the shrimp for at least 30 minutes, flipping once or twice, until all sides have turned from gray to white/pink.

Meanwhile, in a blender, add habanero peppers, a pinch of salt/pepper, and most of the mango (save some extra slices for garnish). Blend until smooth.

After shrimp has fully cooked in lime, add the red onion slices to the shrimp and pour over the mango habanero sauce. Cover and place in refrigerator for about 30 minutes to several hours.

When ready to serve, top with some fresh cilantro leaves. Serve cold atop the tostadas.