Glazed Pork Ribs with Shichimi Togarashi

• 2 racks St. Louis–style pork ribs (about 4 lb.)
• 1 1/2 tablespoons kosher salt plus more
• Freshly ground black pepper
• 1 lemon, very thinly sliced
• 2 sprigs rosemary plus 1 Tbsp. minced
• 1 garlic clove, thinly sliced, plus 1 tsp. finely grated
• 2 tablespoons (or more) fresh lemon juice
• 1 teaspoon finely grated lemon zest
• 1 tablespoon cornstarch
• 1/2 cup thinly sliced scallions 
• Shichimi togarashi*  A spice mix of red pepper that can be found in Asian Markets

1.  Preheat oven to 350°F. 
2. Arrange a double layer of foil on a rimmed baking sheet so foil hangs over sides.
3. Place a large sheet of parchment paper on foil. 
4. Season ribs all over with 1 1/2 Tbsp. salt and pepper.
5. Preheat broiler. Line a rimmed baking sheet with foil.
6.  Cut between bones to separate ribs. 
7. Transfer ribs to prepared baking sheet and broil, turning occasionally, until beginning to brown and crisp, about 10 minutes. 
8. Remove from oven and brush with warm glaze. 
9. Sprinkle with scallions and shichimi togarashi.
10. Place 1 rack of ribs, bone side up, on parchment. 
11. Arrange sliced lemon, rosemary sprigs, and sliced garlic over. 
12. Lay remaining rack over, bone side down, creating a pocket between the racks. (The seasonings in the center will infuse the meat as it bakes.)
13. Cover ribs with another sheet of parchment; crimp edges to seal. (The parchment seals in flavor and prevents the acid from the lemons from reacting with the foil.) 
14. Wrap ribs tightly with foil to form a tight seal (use extra foil, if necessary, to completely enclose ribs, and crimp edges together to tightly seal).
15. Bake ribs for 1 1/2 hours. 
16. Remove from oven and let rest at room temperature, still sealed in foil, for 1 hour. (Do not open; ribs will continue to cook and become tender.)
17. Carefully open foil. Transfer ribs to a platter or another baking sheet; discard lemon slices and rosemary sprigs. 
18. Pour pork juices into a measuring cup. 
19. Add water if needed to measure a scant 1 cup.
20. Bring reserved pork juices, minced rosemary, grated garlic, 2 Tbsp. lemon juice, and lemon zest to a simmer in a small saucepan over medium-high heat. 
21. Whisk cornstarch and 1 Tbsp. water in a small bowl for slurry. 
22. Whisk slurry into juices to thicken (the glaze should just coat the back of a spoon). 
23. Season glaze with salt and pepper and more lemon juice, if desired. DO AHEAD: Glaze can be made 3 days ahead. Cover and chill. Gently rewarm before using.