Coarse salt and ground pepper
12 ounces whole-wheat spaghetti
2 tablespoons olive oil
1/2 medium onion, thinly sliced, lengthwise
2 garlic cloves, thinly sliced crosswise
1/2 cup dry white wine
1 can artichoke hearts, drained, rinsed, and quartered lengthwise
1/3 cup pitted kalamata olives, quartered lengthwise
1 pint cherry or grape tomatoes, halved lengthwise
1/4 cup grated Parmesan cheese, plus more serving
1/2 cup fresh basil leaves, torn