Simplify the following text for a Grade 7 native English-speaking person.
Original: Traditionally , the weight ratio for mirepoix is 2:1:1 of onions , celery , and carrots ; the ratio for bones to mirepoix for stock is 10:1 .
Simplified: Traditionally , the ratio for mirepoix is 2:1:1 of onions , celery , and carrots . The ratio for bones to mirepoix for stock is 10:1 .