Heat extra virgin olive oil in a medium-sized skillet over medium-low heat then add kale, season with salt, and saute until tender, 4-5 minutes. Once cool enough to handle, transfer kale to a cutting board then chop into small pieces and set aside. In a large bowl combine avocados, the juice from 1/2 lemon, garlic, and salt then mash until very smooth (alternatively you could process in a food processor then transfer to a large bowl.) Fold in chopped kale and artichoke hearts then taste and add more salt and/or lemon juice if needed. Serve immediately.