Cook the linguine in a Dutch oven over 15 briquettes, according to package directions. Drain, then cover and place two or three briquettes on top to keep the linguine warm.

Meanwhile, in a second Dutch oven over 9 to 12 briquettes, heat the olive oil. Add the shrimp, garlic, and red pepper flakes and cook until the shrimp are opaque. Using a slotted spoon, transfer the shrimp to the first Dutch oven.

Add the onions to the second Dutch oven and cook for 5 minutes, stirring once or twice. Add the tomatoes, tomato paste, olives, and capers and simmer uncovered for 5 minutes. Stir in the parsley and simmer for 1 minute.

Place the linguine and shrimp on a serving platter and top with the sauce.