Heat oil over medium high heat in a large pot or dutch oven.
Add bell pepper, onion, garlic, salt, and black pepper and stir. Cook until onion becomes translucent, about 4 minutes.
Drop heat to medium heat, add red curry paste, and stir.
Add coconut milk and sugar, and stir until well incorporated.
Place tilapia filets into stew and spoon some stew over them until the filets are covered.
Let tilapia filets cook until they have turned white and flake easily with a fork. I break my tilapia filets up into small chunks which are easier for my children to eat.
Once the fish is cooked, serve warm over white rice.