Slice the chicken breast into 1cm/1/3" thick steaks. Sprinkle with salt and pepper.

Heat the olive oil in a large pot over medium-high heat. Add the chicken in 2 batches if necessary and cook each side for 2 minutes or until golden and just cooked through.

Transfer the chicken to a plate. Once cool, shred with a fork or chop it.

Turn the heat down to medium and add butter into the same pot. When melted, add onion and garlic. Cook for 3 minutes until onion is translucent.

Add flour and cook for 2 minutes, stirring constantly. Add chicken broth, scraping the bottom to stir in the brown bits for extra flavor.

Add milk, cumin powder, coriander, and jalapeños. Turn heat up to medium-high, whisking occasionally until the soup thickens slightly, about 5 minutes.