Quick Ravioli Skillet

Ingredients

• 1 tablespoon extra-virgin olive oil
• 1 medium green bell pepper, thinly sliced
• 1 medium red bell pepper, thinly sliced
• 1 small red onion, halved and thinly sliced
• kosher salt, to taste
• freshly ground black pepper, to taste
• 2 cloves garlic, minced
• 1 (14-ounce) can crushed tomatoes
• 1/4 teaspoon crushed red pepper flakes
• 1 (10-ounce) package Italian sausage ravioli
• 3 slices provolone cheese
• fresh basil leaves, optional, to taste, for serving