Heat the olive oil in a large pot over medium heat. Add the onion, garlic, and ginger and cook for 3 to 4 minutes until the onion softens.
Stir in the Thai red curry paste and cook for 1 minute until fragrant.
Add the red lentils, vegetable broth, and sliced red bell pepper. Bring to a simmer, then reduce heat and cook for 15 minutes, stirring occasionally.
Pour in the coconut milk and stir to combine. Continue simmering for another 5 minutes.
Add the halved baby bok choy and cook for 3 to 4 minutes until the leaves wilt and the stems become tender but still have some bite.
Remove from heat. Stir in the lime juice and season with salt to taste. Sprinkle with chopped cilantro before serving.