In a large bowl, whisk together the EVOO, tamari (or liquid amino), balsamic, honey (or agave), garlic, fennel seeds, red pepper, lemon zest and juice. Preheat an outdoor grill or indoor grill pan to medium-high. Place the chicken in the bowl with the sauce and let marinate for 10 minutes, turning occasionally.
In a large, deep skillet, bring 1 inch water to a boil and cook the asparagus for 2 minutes. Shock the asparagus in ice water and drain well.
Grill the chicken for 12 minutes, turning occasionally; transfer to a plate and tent with foil. Grill the asparagus to mark evenly, 3 to 5 minutes. Slice the chicken and layer with the asparagus. Top with the scallions and drizzle with harissa sauce (or sriracha).