Preheat your oven to 425ºF. Line 2 rimmed baking sheets with parchment paper.
Toss the radishes in 1.5 tablespoons olive oil. Spread on 1 of the baking sheets. Season the radishes with kosher salt + black pepper.
Roast the radishes for 45-50 minutes. You're going to start the radishes first because they take longer to roast and need a head start.
25 minutes after you start the radishes, drizzle the chicken breasts with 1 tablespoon olive oil. Season both sides with the jerk seasoning. Place on the baking sheet.
Toss the brussels sprouts in 1.5 tablespoons olive oil. Spread on the baking sheet with the chicken breast. Season the brussels sprouts with kosher salt + black pepper.
Add the baking sheet to the oven with the radishes and roast for 20-25 minutes, until the brussels sprouts are soft and the chicken has an internal temperature of 165ºF.
In a small bowl, combine the mayo, lime zest, lime juice, garlic + salt. Stir to combine.
Serve the jerk chicken warm topped with 2 tablespoons of the garlic lime aioli, along with the roasted radishes and brussels sprouts.
Tips, FAQs and substitution info in the Recipe Notes below!