Based on the level of respect or formality, you can say "I am a cook." in Korean in 3 ways:

• Informal: na-neun jorisa-ya. (나는 조리사야.)
• Formal: na-neun jorisa-yeyo. (나는 조리사예요.)
• Very formal: jeo-neun jorisa-imnida. (저는 조리사입니다.)