3 tablespoons extra-virgin olive oil (plus more if needed)
1/2 cup onion, chopped
3 medium zucchini
4 cloves garlic, minced
1 pint cherry (or grape) tomatoes, halved
1/3 cup low-sodium chicken broth
1/4 to 1/2 teaspoon crushed red pepper flakes (or more to taste)
Salt and freshly ground black pepper
1 tablespoon chiffonade of fresh basil
Put a large pot of salted water on to boil for the tortellini.
Quarter each zucchini lengthwise, then slice crosswise into 1/2-inch pieces.
Coat a large frying pan with the olive oil and place over medium heat. Add the onion and cook until soft and translucent, 3 to 4 minutes.
Add the zucchini and continue cooking for 3 to 4 minutes longer, stirring frequently.
Stir in the garlic and continue cooking until the zucchini is lightly caramelized, 2 to 3 minutes more.
Add the tomatoes, stir in the chicken broth, sprinkle with crushed red pepper and continue cooking until the tomatoes have softened slightly and their juices blend with the broth to form a light sauce.
Season to taste with salt and pepper and remove the pan from the heat while you cook and drain the tortellini.
Once the tortellini is cooked, add the basil to the zucchini-tomato mixture, then toss with the tortellini.
Taste and adjust the seasoning and drizzle with a bit of extra olive oil if needed. Serve immediately.