Heat oil in a pressure cooker over medium-high heat ("sear" setting on an electric pressure cooker) until shimmering. Add garlic, chilies, ginger, coriander, and cumin and cook, stirring, until aromatic, about 1 minute. Add curry paste and cook, stirring, until paste has darkened slightly, about 3 minutes.
Step 2
Stir in coconut milk, bring to a simmer, and cook for 1 minute. Season chicken pieces with salt. Add half the squash and eggplant and season with salt. Add chicken and top with the remaining squash and eggplant. Season with salt. Seal pressure cooker and cook on high pressure for 20 minutes.
Step 3
Release pressure, remove lid, and stir in fish sauce, spinach, and 1/4 cup each of the cilantro and Thai basil. Season with salt and pepper. Ladle the stew into serving bowls and scatter remaining cilantro and basil on top. Serve with rice and lime wedges.