In a medium straight-sided pan, heat 2 tablespoons of oil over medium-high heat and saute the chorizo and onions, breaking the chorizo up with a wooden spoon while cooking until it resembles ground beef. Add the adobo, paprika and a few grinds of black pepper. Cook until the fat is rendered and the onions are tender and cooked into the chorizo, 8 to 10 minutes.
Add the remaining oil and the garlic and lower the heat to medium-low. Let the flavors infuse over the low heat for 5 to 7 minutes. Add the shrimp to the garlic oil, raise the heat slightly, and stir and turn to cook the shrimp evenly, 6 to 8 minutes. Serve as an appetizer on toothpicks with crusty, chewy bread.