1

Toss together onion, vinegar, and 1/4 teaspoon salt in medium bowl; set aside, stirring occasionally. Stir together pineapple juice, chile powder, garlic, cumin, oregano, and remaining 1 teaspoon salt in large glass measure; reserve.

2

Cut pork into 3 large pieces. Trim away visible fat and connective tissue; cut pork into 2-inch chunks.

3

Press Sauté on 6-quart Instant Pot and set cooking time for 15 minutes. When Hot is displayed, spray pork with olive oil nonstick spray. Put pork into pot and cook, turning occasionally, until browned, about 10 minutes. Add pineapple juice mixture to pot, stirring to scrape up browned bits from bottom of pot. Press Cancel to turn off pot. Lock lid, making sure vent is closed.

4

Press Pressure Cook and select High Pressure; set cooking time for 35 minutes. When time is up, press Cancel to turn off pot. Move steam release valve to Venting position to quickly release pressure; remove lid. With slotted spoon, transfer pork to large bowl. Let stand 5 minutes. Using two forks, shred pork. Cover to keep warm.

5

Transfer sauce in pot to 2-cup glass measure; skim off and discard fat from surface. Add 1/4 cup sauce to pork and stir until coated evenly. Transfer onion to sieve to drain. Line taco shells with lettuce and top evenly with pork, onion, and radishes. Serve with remaining sauce and lime wedges.

6

Per serving: 1 taco