Step 1

Heat a large sauté pan over medium heat. Add the olive oil. Once hot, add the red onion and shallot. Season with a pinch of salt. Cook for 8 minutes, stirring often, until tender and caramelized. Add a little bit more olive oil, and reduce the heat to low. Cook for another 8 minutes until the onions are deeply caramelized. Stir in the red fresno chiles and cook for about 3 minutes longer.

Step 2

While the onions cook, bring a large pot of water to a boil. Add a heaping amount of salt to the water. Drop the linguine and cook for 2 minutes less than the package instructions. Right before the linguine is ready, reserve 2 cups of pasta water.

Step 3

Add the butter to the spicy onion mixture and let melt. Pour in 1 cup of the pasta water. Let simmer for a minute or so. Drain the pasta and add it right into the pan. Toss to combine and finish cooking for another 2 minutes.

Step 4

Stir in the grated parmesan cheese. Mix really well while the cheese melts into the sauce. Continue to add more pasta water if needed to keep the sauce nice and silky. Stir in the oregano right before serving.

Step 5

Plate the pasta, spooning all of the onions and sauce over top. Garnish with more parmesan cheese, fresh oregano, and lots of freshly cracked black pepper.