Step 1

Preheat the oven to 350F.

Step 2

Roast the tomatoes: Slice the tomatoes in half. In a small bowl, stir them together with the olive oil and 1 generous pinch kosher salt. Place them on a parchment paper lined baking sheet face up and spread them evenly apart. (You can also place some of the tomatoes face down for a delicious sundried tomato effect; they loose their shape and blacken a bit more but are still delicious.) Roast the tomatoes for 40 minutes, then allow them to cool for at least 5 minutes.

Step 3

Boil the pasta: Meanwhile, bring a large pot of salted water to a boil. Cook the pasta until just al dente (cook until just tender but still a bit firm).

Step 4

Grate the white cheddar cheese.

Step 5

Make the cheese sauce: In a large saucepan or Dutch oven, heat the butter over medium heat; when it melts, stir in the flour. Heat the mixture for several minutes, stirring constantly. Immediately when the color starts to turn light brown, reduce the heat to low. Start to add the milk very slowly, whisking constantly until the mixture is completely smooth, then adding more milk. Add the salt, onion powder, and garlic powder, and continue cooking on low heat for 4 minutes until slightly thickened. Remove from the heat, then add the grated cheddar cheese and keep stirring until it is melted and a smooth, thick sauce forms (if necessary, return the heat to low to finish melting the cheese).

Step 6

Finish the dish: Add the pasta to cheese sauce and stir to combine. Then pour the pasta into a serving dish. Top it with tomatoes and serve immediately.