Salmon With Citrus-Chile Sauce

4 jalapeños, seeds removed (leave some seeds in if you like more heat)
2 garlic cloves
Kosher salt
Zest of ½ grapefruit
2 tsp. honey
6 Tbsp. extra-virgin olive oil, divided
2 bunches broccolini, cut into 2" pieces
4 (5–6-oz.) skin-on, boneless salmon fillets
2 Belgian endive, leaves separated, cut into large pieces
¼ cup fresh grapefruit juice
3 Tbsp. unseasoned rice vinegar
Toasted sesame seeds (for serving)

Pulse jalapeños, garlic, and a pinch of salt in a food processor to a coarse paste (you can also smash with a mortar and pestle or finely chop jalapeños and garlic on a cutting board, sprinkle with a pinch of salt, and crush with the side of a chef’s knife).
Transfer paste to a small bowl and add grapefruit zest, honey, and 2 Tbsp. oil; toss to combine. Set sauce aside.
Heat 2 Tbsp. oil in a large nonstick skillet over medium-high. Add broccolini and cook, tossing occasionally, until crisp-tender and charred in spots, about 5 minutes. Divide among plates.
Heat remaining 2 Tbsp. oil in same skillet over medium. Season salmon with salt and cook, skin side down, until skin is browned and crisp, 6–8 minutes. Turn and cook on flesh side just until cooked through, about 1 minute.
Add endive to broccolini on plates; season with salt. Set salmon on top. Stir grapefruit juice and vinegar into reserved sauce and spoon over salmon and vegetables. Sprinkle with sesame seeds.