In a bowl, combine the chicken breasts, 2 tablespoons avocado oil, smoked paprika, Italian seasoning, 1 teaspoon salt and ½ teaspoon black pepper. Toss everything to coat, cover and refrigerate 1 hour to overnight.
Preheat your grill or oven to 450F. If using a gas or charcoal grill, setup a two-zone fire with medium heat on one side.
In a bowl, combine the sweet potatoes, 2 tablespoons avocado oil, ½ teaspoon salt, and ¼ teaspoon black pepper and toss to coat. Transfer the sweet potatoes to a sheet pan lined with parchment paper, arrange in a single layer, and place on the indirect-heat side of the grill or in the oven. Cook, tossing halfway, until the sweet potatoes are fork-tender and golden brown, around 20 minutes total. Around 5 minutes before the sweet potatoes are finished cooking, add the walnuts to the sheet pan and let them toast until golden. Remove the sheet pan from the grill and set aside.
Meanwhile, place the chicken onto the direct-heat side of the grill, or a grill pan over medium heat, and cook, flipping halfway, until grill marks form and the thickest part of the breast registers 160F, around 14 minutes total. Transfer the chicken to a cutting board and let them rest 8 minutes before thinly slicing.
Add the kale to a large bowl and pour in the Maple Tahini dressing. Using your hands, massage the kale for 2 minutes until it is completely soft and well coated in the dressing. Add the Brussels sprouts, green and red Grapes from California, roasted sweet potatoes and toasted walnuts. Toss everything to coat and transfer onto individual serving plates. Garnish with freshly-grated pecorino cheese and top with the sliced chicken breast. Drizzle with a small amount of olive oil and serve.