Can vegetables be roasted at lower temperatures? I tried to bake some new potatoes, small tomatoes and hot peppers, in extra-virgin olive oil, using a recipe calling for 1 hour at 100° C.

I was skeptical of the 100° C temperature, so I set the temperature to 120° C instead. However, even after 3 full hours of roasting, the vegetables still had a raw tang, and the texture of the potatoes was a bit rubbery.

What could have been the problem here? Is 120-140° C too low for these vegetables?

(Note: At one point I turned on the ventilation mode, and it seemed to start cooking much faster - maybe even a little too fast. Could the recipe have been intended for a convection oven?)
Slow roasted vegetables are delicicous. But the accent is upon slow - at 100 degrees you could be talking 6-8 hours. It's very similar ti slow cooked lamb, use lots of olive oil and wait.

I like to put in slices of potatoes for the first three hours and then add pepper courgettes, and other vegetables needing less cooking time for the kast 3 hours.

Great to serve with a half peanut butter, half feta cheese thick dip and some crispy toasted pitta bread.