Step 1

Prepare a grill for medium indirect heat (for a charcoal grill, bank coals on one side of grill; for a gas grill, leave one or two burners off). Thread shallot and garlic onto a metal skewer. Arrange skewer and tomatoes on grate over direct heat and grill, turning halfway through, until skins are blistered and charred and flesh is slightly tender, 10–12 minutes per side. Transfer skewers and tomatoes to a large plate; remove skins from shallot and garlic.

Step 2

Combine tomatoes, shallot, garlic, cilantro, lime juice, chiles, fish sauce, and brown sugar in a blender and blend to a coarse sauce. Transfer to a bowl.

Step 3

Place eggplant, skin side down, on a rimmed baking sheet. Drizzle with oil and season with salt. Turn over and drizzle with oil and season with salt again.

Step 4

Place eggplant, cut side down, on grate over indirect heat. Cover and grill until slightly golden brown and flesh is tender, 18–20 minutes. Move eggplant over direct heat (still cut side down) and grill until cut sides are charred, 8–10 minutes. Transfer to baking sheet and arrange skin side down. Slightly mash flesh with a fork or butter knife.

Step 5

Arrange eggplant on a platter. Drizzle tomato sauce over, and top with peanuts, chiles, and cilantro leaves.