Heat oil in a large skillet over medium-high heat. Add curry paste with garlic, ginger, and lemongrass and cook for 2 minutes until it dries out.

Add chicken broth and stir to dissolve the paste. Simmer for 3 minutes until the liquid reduces by half.

Add coconut milk, kaffir lime leaves, sugar, and fish sauce. Stir and add the chicken. Simmer for 8-10 minutes until the sauce reduces and chicken cooks through.

Add the pumpkin and green beans and cook for 3 minutes until tender and the sauce thickens. Taste and adjust seasoning with additional fish sauce or sugar.

Remove from heat and stir through Thai basil. Serve over jasmine rice, garnished with chili slices.