Rinse the shrimp and pat dry with a paper towel. In a large skillet, over high heat, melt 2 tablespoons of butter. Add the shrimp and spread across the pan in a single layer. Let it cook without touching it for about 1 minute. Flip the shrimp over and cook an additional minute. When the shrimp is light pink and cooked through, remove to a plate.

Reduce the heat to medium high and add a drizzle of oil to the hot pan. Toss the peppers in the oil and let them cook until they are slightly browned and barely softened, about 2 minutes. Add the pineapple, toss with the peppers, and let it soften slightly, about 1-2 minutes.

Add the barbecue sauce, stir, and increase the heat to high. When it starts to simmer, return the shrimp to the pan, toss everything together to coat well, and cook for about a minute as the sauce thickens slightly. Remove from the heat and add the green onions. Serve by itself or over rice.