Soak the walnuts for at least 2 hours and drain. Preheat a grill to high. Grill the whole eggplants with the lid closed, flipping occasionally, until charred and collapsing, 20-25 minutes. Set aside in a bowl to cool. Heat 1½ tbsp olive oil in a large sauté pan over medium heat. Add the breadcrumbs, cumin, chili flakes, salt and pepper. When the edges darken, lower to medium-low and stir until evenly toasted, about 5 minutes. Stir in the dill and transfer to a plate. Halve the eggplants and scoop out the flesh, pouring off excess liquid. Blend with the walnuts, lemon juice, miso, ½ tsp of the garlic, salt and pepper until smooth. Cook the pasta in salted water and reserve 1 cup of cooking water before draining. Heat the remaining oil in the pan over medium heat. Sauté the shallots and remaining garlic until soft, about 5 minutes. Lower the heat to medium-low. Add the sauce, the pasta, salt and pepper, and stir. Loosen with pasta water as needed. Top with the breadcrumbs, extra dill and chili.