Preheat oven to 400 degrees. Halve 1 garlic clove. Halve the baguette lengthwise and rub the cut side with the halved garlic. Halve, peel, and thinly slice the onion. Chop the sun-dried tomatoes. Mince all remaining garlic. Pick the oregano leaves off the sprig and mince.

Heat 1 tablespoon olive oil in a large pan over medium-high heat. Add the onion, sun-dried tomatoes, and 1/4 teaspoon chili flakes (or more!) to the pan and cook, tossing, until onion is soft, about 5 minutes. Stir in the minced garlic and oregano and cook for 30 seconds, until fragrant. Season with salt and pepper.

Add the diced tomatoes, stock concentrate, and 16 cup water to the pan. Reduce the heat to medium-low and simmer for 10 minutes, until sauce has thickened. Season with salt and pepper.

Season the shrimp with salt and pepper, then stir into the sauce and cook for 3-4 minutes, until just pink and opaque.

Meanwhile, drizzle the baguette with 1 tablespoon olive oil and season with salt and pepper. Toast on a baking sheet in the oven for 3-4 minutes, until golden brown and crispy.

Serve the shrimp fra diavolo sprinkled with chili flakes (if you can take the heat!) and garlic crostini to the side. Buon appetite!