Heat the olive oil over very low heat in a large skillet. Add the garlic and cook for 3 to 4 minutes. Do not let the garlic burn.Add the shrimp and cook until they are pink all over. Season with salt and pepper to taste.Remove from heat and set aside.
Heat the frying oil over medium heat (175 ºC [350 ºF]) in a small bowl or saucepan.Fry each plantain slice until light golden brown (about 5 minutes). Press the slices with a lemon squeezer to form small cups.Once all the cups are formed, fry them again over medium-high heat until they turn golden brown.
Peel the avocado and crush using a fork until it doesn't have any lumps. Season with salt and pepper to taste. Mix in the lime juice.
Spoon about tablespoons of avocado mix into the cups.Top each with a shrimp and garnish with cilantro leaves.Serve immediately.