Combine Smoky Spice Rub ingredients.
Place pork on large sheet of plastic wrap and brush with ½ tablespoon olive oil. Sprinkle evenly with Smoky Spice Rub. Cover and refrigerate for at least 30 minutes or up to 12 hours.
To make Spring Mixed Pea Salad, heat 1 tablespoon olive oil in skillet over medium heat. Add onion and cook 6 minutes or until softened. Remove from heat and stir in 1 tablespoon lemon juice. Set aside.
Bring a large saucepan of water to boil. Add peas and sugar snaps and boil 2 minutes, until vegetables are crisp-tender. Rinse under cold running water and drain well.
Whisk together tarragon, lemon rind (optional), mustard, sugar, salt, remaining 3 tablespoons olive oil and remaining 3 tablespoons lemon juice in large bowl until blended. Toss in onion and drained peas.
Preheat grill to medium heat. Grill pork, turning occasionally, until it registers 135°F on an instant-read thermometer, about 20 minutes. Let stand 10 minutes, slice, and serve with pea salad.