Prepare pasta according to package directions; drain.

Brush the red pepper strips and onion rings lightly with the vegetable oil. Over medium-hot coals, grill the vegetables until they are very soft, about 8 to 9 minutes.

Mince the tomatoes and put them in a large bowl. Stir in the scallions, jalapeños, lime juice and salt.

When the peppers and onions are ready, transfer them from the grill to a cutting board. Cut them into very thin strips and add to the salsa with the pasta. Toss well.

Divide the pasta among four bowls and top each with a spoonful of sour cream.