Heat 1 tbsp. oil in a small frying pan over medium heat. Add pumpkin seeds and cook, stirring often, until golden, 6 to 8 minutes. Transfer with a slotted spoon to paper towels and sprinkle with 1/8 tsp. salt.
Juice enough tangerines to make 1/2 cup. Peel remaining fruit and slice crosswise about 1/3 in. thick.
In a small bowl, whisk tangerine juice, lemon juice, remaining 2 tbsp. oil, the ground chile, remaining 3/4 tsp. salt, and the pepper. Chop 2 tsp. mint and stir into dressing.
Set a bed of lettuce on plates. Arrange tangerines, avocado, and jicama on top. Drizzle with dressing and sprinkle with pumpkin seeds and remaining mint.
*Find at well-stocked grocery stores and oaktownspiceshop.com.