This is most likely calculated using a non-normalised trailing...

This is most likely calculated using a non-normalised trailing pe, which given the circumstances I don't think is a very reliable method of calculating pe.

1H FY2022 eps was 9.3 cents
Full Year FY2022 eps was 8.0 cents
Decline of 1.3 cents eps
1H FY2023 eps is 2.4 cents
Therefore trailing 12 months non normalised eps 1.1 cents
3.30/0.011 =pe of 300

A normalised pe provides a different picture:

Full year FY2022 normalised eps 15.2 cents
1H FY2022 normalised eps 11.7 cents
15.2-11.7 = 3.5
1H FY2023 normalised eps 3.1 cents
Trailing 12 months normalised eps = 6.6 cents (3.5 + 3.1)
Puts normalised trailing pe at around 50 (3.3/0.066)

Unless projecting a second half loss, forward pe is unlikely to be as high as 300.

Forward pe should be better as lagging price increases continue catch up to increased input costs (improved gross margin), and covid expenditure from FY2022 is phased out of calculations (basic eps will return closer to the normalised eps).

Also remember the vitasoy payout of 51mil. Future bottom line will drop due to reduced ongoing revenue, however payout will result in non-normalised bump in 2H earnings of approx 14.7 cents per share (51mil/303mil shares = 16.8, of which approx 2.1 cents will contribute to the most recent dividend payout (0.045 div - 1H 0.024 eps = 0.021; 16.8-0.021 =14.7)).