Cook pasta: Bring a large pot of salted water to a boil. Cook 4 ounces dried short pasta according to package instructions until just before al dente. Reserve ½ cup pasta water and drain pasta.
Cook the alliums: Meanwhile, in a large skillet, melt 2 tablespoons unsalted butter over low heat.Add 1 shallot, 2 garlic cloves, and 1 tablespoon water, and saute for 5 - 8 minutes until they are soft (but not brown) and translucent. Season with a pinch of salt.Note: If the onions begin to brown at all, add a splash of water and lower the heat.
Add the pastes: Over medium-low heat, add 1 tablespoon mild gochujang paste* and 2 tablespoons tomato paste. Cook down for about 2 - 3 minutes, stirring frequently until any remaining moisture evaporates from the puree. The paste should darken to brick-red and begin to stick to the sides of the pan.
Simmer: Whisk in ½ cup heavy cream. Simmer for 5 - 8 minutes, stirring occasionally, until the sauce is thick enough to coat the back of a wooden spoon and transforms from salmon pink to bright orange.Note: Don't be afraid to let the cream sauce simmer and thicken! It's an essential step to ensuring a glossy, vibrant sauce.
Finish the sauce: Season sauce with salt, and reduce heat to low. Stir in 2 tablespoons of grated parmigiano-reggiano cheese¼ cup loosely packed grated parmigiano-reggiano cheese and the cooked pasta into the sauce.
Loosen the sauce with a few tablespoons of reserved pasta water, then reduce for 1 - 2 minutes until the sauce looks glossy and clings to the pasta. If needed, add more pasta water to achieve your desired consistency.Taste and season again with salt and additional gochujang paste if desired.
Divide amongst serving bowls, and top with the sliced scallion, remaining cheese, and sesame breadcrumbs (if using). Serve immediately and enjoy!
Set a small saucepan over medium-low heat and add 1 tablespoon extra-virgin olive oil. Stir in ¼ cup panko breadcrumbs and 2 tablespoons sesame seeds, and toss to coat. Toast breadcrumbs and seeds until nicely golden brown, about 2 - 3 minutes. Remove from the heat and stir in the grated 1 garlic clove. Season with salt, then top the pasta and enjoy.
