Depending how much chipotle pepper you add, it's either very spicy-hot, or not very spicy-hot. Your call! In either case, a delicious way to prepare shrimp! Exceedingly popular at my 44th Birthday Party.
To roast the flavorings, cook garlic on ungreased griddle or in a heavy skillet over medium heat, turning occasionally, until soft, about 15 minutes; they will blacken in spots. Meanwhile, lay the onion slices on a piece of foil on the griddle (or under the broiler) and cook until browned and soft, about 5 minutes per side. Roast tomatoes on a baking sheet in the broiler until blackened in spots and soft, about 6 minutes per side. Cool and peel, collecting all juices. [Peeling optional - mrm.]
Puree garlic, onion and tomatoes in a blender or food processor with pepper, cloves and water. [I put whole cloves in food processor, and that works fine. -mrm.]
Heat oil in a large skillet over medium-high heat. When hot, add puree all at once. Cook and stir several minutes until mixture darkens, then reduce heat to medium-low and continue cooking and stirring until mixture is very thick, about 5 minutes.
Sire in the chipotles a tablespoon at a time, tasting after each addition, until the level of spiciness suits your taste. Add salt to taste.
At this point, you can set chipotle sauce aside, and reheat when you're ready to cook the shrimp.
Add shrimp, raise heat to medium high and cook, stirring slowly, 3 to 4 minutes or until shrimp are just cooked through.
Serve hot or at room temperature.
This makes 6 servings. The sauce can be made several days ahead of time and refrigerated.