Warm Pasta Salad with Roasted Corn and Poblanos

1 fresh jalapeño chile

8 medium tomatoes (2 lb), coarsely chopped

3 tablespoons chopped fresh oregano

2 tablespoons chopped fresh cilantro

1/3 cup green (hulled) pumpkin seeds

4 ears fresh corn, kernels cut off

1 large white onion, cut into 1/2-inch-thick rounds

3 garlic cloves, minced

1 teaspoon ground cumin

1/4 cup olive oil

12 oz short pasta such as gemelli or rotini

1 1/2 cups crumbled queso fresco (Mexican fresh cheese) or ricotta salata cheese

Garnish: fresh cilantro leaves