1. Combine flour and ¼ tsp. salt in a large bowl and make a well in the center. Mix olive oil with 1 cup water in a small bowl and gradually add to well, whisking constantly, until flour is incorporated and batter is smooth. Cover with plastic; set aside for 2–3 hours. Just before frying, whisk egg white in a bowl until stiff peaks form, then fold into batter.

2. Stir lemon juice into a large bowl of water and set aside. Trim stems and top one-third off of artichokes with a sharp knife, then snap off dark outer leaves and chop leaves off at "waist." Scoop out choke from medium artichokes with small spoon, then cut hearts into quarters, or cut baby artichokes in half lengthwise. Put artichokes into lemon water.

3. Pour oil into a medium pot to a depth of 2" and heat over medium-high heat until hot, about 375° on a candy thermometer. Working with a few pieces at a time, pat artichokes dry, then dip into batter and deep-fry until crisp and golden, about 4 minutes. Transfer artichokes with a slotted spoon to paper towels to drain, and season generously with salt. Serve with hot California-Style Tartar Sauce, if you like.