Oven – Convection/Steam cooking in a Normal Oven

Toaster ovens are awesome. For a toaster oven, there are three key features:

1. Big enough to fit the largest item you'll cook.
2. Convection, so food cooks quickly and evenly.
3. Enameled or stainless/aluminum interior. This lets you use harsh abrasives to keep it clean.

It's a given that your oven should have bake, broil, and roast modes.

For size, you'll probably want it big enough to comfortable fit a 1/4 sheet pan, or a 9" x 12" brownie pan. That will allow you to bake. Much bigger and it will take up a huge amount of counter space and realistically you should use a full oven for the big stuff. Too small and you'll have to fire up the full oven for everything, which defeats the purpose.

Convection makes a huge difference in toaster ovens; because they're so small, they are more prone to uneven heating than normal ovens, and leak heat out the front. If you open them to move food, they'll lose most of the heat, and take a while to get back up to temperature without convection. Convection lets you cook faster and more evenly.

For cleaning and long-term use, you need to be able to scour off the burned-on crap with steel wool or other harsh abrasive. Otherwise the oven will quickly become so unsanitary that it must be replaced, and nonstick finishes never last. The bottom will, of course, be lined with aluminum foil for easy cleanup of drips.

Oh, and rotisserie is a useless gimmick. I've had it on ovens, and never used it yet. Other people may have different experiences with it, of course, but that's my $0.10.

Note: I am assuming this glass is kitchenware, like mixing bowls or measuring cups, not service ware like drinking glasses or teacups.

Glass melts at about 1500 F / 800 C. There is no danger of melting the glass in any type of steamer, or realistically with any equipment you may have at home.

The real issue is thermal shock: very rapidly cooling glass from a hot temperature to a cold temperature can cause it to crack or shatter. You want to avoid doing this. The same thing can happen in reverse from cold to hot, which is why you would never use glass cookware on an open flame or burner element of your cooktop (hob to our British friends).

To prevent thermal shock, even in a closed pot used as an improvised steamer, do not place the glassware directly on the bottom of the pot. It should be suspended on a rack or otherwise raised from the bottom. If no other solution presents itself, aluminum foil loosly crushed into a ring will do the job (loosly, because aluminum is a good conductor or heat, but air is not).

Steaming is fairly gentle in terms of heating, and if you let it cool on the counter, you should be fine. Note that I would not do this with any delicate or thin glass. Think about it this way: if you would use the glass in the microwave, the steamer should be fine as well.

Of course, you can always steam on a lettuce leaf or similar, which is very traditional, or use a metal steamer basket as well.

Please also see Rumtscho's answer for more optimal alternatives.