Preheat the oven to 400F.
In a large bowl, whisk together the eggs, yogurt, and ¾ teaspoon salt.
In a 12-inch oven-proof skillet over medium heat, warm the olive oil. Add the onion, ¼ teaspoon salt, and pepper and cook until softened, stirring occasionally, about 5 minutes.
Add artichokes, spinach, and remaining ½ teaspoon salt. Cook until the spinach has wilted completely and any water it gave off has evaporated, about 5 minutes, stirring occasionally.
Slowly pour the egg mixture evenly over top. Give the pan a shake to make sure the egg is evenly distributed. Crumble the goat cheese on top. Cook until you notice the edges start to set. This will take about 5 minutes.
Transfer to the oven for 10-15 more minutes, or until the center of the frittata is cooked through (it’s okay if it’s slightly jiggly in the center, it will continue to cook as it sits). Let it rest for at least 10 minutes before slicing.
In a small bowl, mix together the herbs, lemon and salt. Serve the sliced frittata with a side herb salad.