Place serrano pepper, garlic clove, iceberg lettuce, mayo, cilantro. in a food processor and pulse until blended. squeeze in lime juice, cilantro, cumin, smoked paprika and salt. blend until smooth. Store in the fridge until ready.
FOR THE TACOS
Cut open your lobster tails and remove the meat. Place in a bowl and season with salt and pepper.
In a pan, melt some butter in with the oil and with a clove or two of garlic and let it simmer on low for about 3-5 minutes until aromatic.
Preheat grill on high. Toss about 2 tbsp of the garlic butter into the bowl of lobster tail meat and toss. Squeeze in some lemon juice and place on the grill.
Grill tails for about 5-7 minutes until they're opaque and just begin to curl. Remove from the grill and chop into bite size bits. Toss in a bowl with the remaining garlic butter.
Place on some tortillas with cabbage and radishes. Pour on some of that spicy green sauce and enjoy!