Whisk aioli in a small bowl. Set aside.
Toss peppers and onions with the garlic herb seasoning (or whatever other spices you want). Drizzle with enough oil so they won’t stick on the grill.
Place sausages directly on the grill. Place peppers and onion slices in a grill basket or a cast iron pan on the grill. Grill both until you get nice grill marks and the veggies are soft. At the end of grilling time, add the brioche buns, cut side down, to get them toasty.
Transfer peppers to a bowl and toss with lemon juice, more olive oil as needed, and salt and pepper to taste.
Serve each grilled chicken sausage on a toasted bun with a scoop of grilled peppers and a swizzle of your aioli. YUM. At our house, extra aioli was requested for certain grown-ups for “dipping,” so just be prepared for that.
