Heat a gas or charcoal grill to medium heat.
Peel and trim the ends off the carrots. Cut crosswise into approx. 3" lengths. Halve lengthwise any thick pieces, or quarter lengthwise if really thick.
In a large bowl, toss the carrots with the avocado oil and za'atar until thoroughly coated.
Place the carrots on the grill (perpendicular to the grates so they don't fall through) and cover. Grill for 6-10 minutes per side, depending on the thickness of the carrots and the temperature of the grill.
To make the sauce, add the mayonnaise to a medium bowl. Zest both limes into the mayo. Halve and squeeze one lime to get about 2 tsp. juice and add to the mayo. Add the salt and fresh ground pepper, stir until blended and taste to adjust seasonings. Cut the other lime into wedges and reserve.
Add the pine nuts to a small, dry skillet. Place over medium heat and cook, tossing and stirring occasionally, until aromatic and golden, about 5-7 minutes. Remove the nuts to a small bowl and set aside.
Spoon about ⅓-½ of the sauce on your serving platter (so the carrots on the bottom get some sauce - everyone likes a saucy bottom). Pile the carrots on top. Spoon the rest of the sauce on top and sprinkle with the mint, chile, pine nuts, a squeeze of a reserved lime wedge, flaky sea salt and fresh ground pepper.