Hawaij Sweet Potatoes With Roasted Lemon Relish and Yogurt

Name: Hawaij Sweet Potatoes With Roasted Lemon Relish and Yogurt
Ingredients: 2 Tbsp. cardamom pods; 1½ Tbsp. coriander seeds; 1 Tbsp. cumin seeds; 2 tsp. fenugreek seeds; 1 tsp. whole cloves; 2 tsp. whole black peppercorns; 1½ Tbsp. ground turmeric; 1 lemon, scrubbed, halved; ¼ cup extra-virgin olive oil; 1 tsp. Savory Hawaij or curry powder; ½ tsp. ground cumin; 6 medium sweet potatoes, scrubbed, halved lengthwise; 1 tsp. kosher salt; Freshly ground black pepper to taste; ½ cup extra-virgin olive oil; ¼ cup fresh mint leaves, finely chopped; ¼ cup fresh flat-leaf parsley leaves, finely chopped; 1 jalapeño, seeded, minced (optional); 1 small shallot, minced; 1 small garlic clove, finely chopped; ¾ tsp. kosher salt; 1½ cups full-fat Greek yogurt; 2 Tbsp. fresh lemon juice (about ½ lemon); Flaky sea salt to taste; 1 tsp. cumin seeds, toasted in a dry pan until fragrant; Fresh mint and/or parsley leaves, for serving