For anyone else scratching their head, here’s what I surmised with all this great feedback (and a little additional research):
1) It looks like there is no such thing as a simple conversion table to use a conventional recipe in a microwave convection (there are for non-microwave convections).
2) My oven has a “sense” mode for various dishes, but for frozen entrees, it is only accurate for 6 – 17 oz packages.
3) The cookbook recommends "Low Bake" mode for frozen entrees, but doesn’t tell you how to determine how long to set it (Low Bake means 325 temp, augmented by 10% microwave, you pick the time - no other controls).
Here’s what I did: The entree was 30 oz, and called for 27 – 29 minutes at 425. I guessed and cooked it for 25 minutes on Low Bake. It came out fine.
Bottom line – either use dishes that fall within the “automatic” modes, or guess/practice a little.
