Easy Green Chicken Enchiladas

Ingredients

• Extra-virgin olive oil
• 1 small yellow onion, chopped
• 2 garlic cloves, chopped
• Kosher salt
• 1½ cups store-bought green enchilada sauce
• 6 to 8 flour tortillas (we used fajita-size)
• 2 to 3 cups shredded chicken
• 1 cup shredded cheese (such as a Mexican blend)
• Chopped red onion, sliced jalapeño, sour cream, avocado and chopped cilantro, to serve (optional)