Combine the shrimp with the marinade ingredients in a food-storage bag. Chill for an hour or so.
Make the dressing. Combine the garlic, jalapeno, tequila, Grand Marnier, lime juice and cumin in a small saucepan over medium-low heat. Bring to a light boil and reduce by about a third. Pour the pan contents into a bowl, and cool. Whisk in the olive oil, then add the cilantro. Season with salt and pepper to taste.
Make the jalapeno cream sauce by combining all the ingredients in a small bowl. Whisk to combine thoroughly. Season to taste. Refrigerate.
Now make the salad. In a large bowl, combine the lettuce, tomato, pepper, avocado and black beans.
Heat a large, heavy skillet over medium-high heat. Add the shrimp and all marinade ingredients. Cook the shrimp until fully cooked--two or three minutes.
Toss the salad with the margarita dressing. Drizzle four chilled plates with cilantro cream. Place salad in center of plates and sprinkle with tortilla chips. Arrange six shrimp on each plate, garnish with lime wedge and a sprinkle of chili powder, and serve immediately.
