Ratatouille, Occitan: ratatolha, is a French Provençal dish of stewed vegetables which originated in Nice, and is sometimes referred to as ratatouille niçoise. Wikipedia
I have copied the pixar film version which is a layered baked version which is more photogenic then the stew and is considerably less work and you will get way more kudos for it in a dinner/retreat party setting.
Now the most important piece of equiptment is a mandoline or a food processor for this one, as it will save about 2 hour of your life.
All ingredients are cut to the same thickness and then placed in the tray either in a circle or in rows with different colours touching.
Dried spices: thyme and dill
Fresh herbs: oregano and basil
6 large Tomatoes
Can of passata
Cook the onion, and garlic to make a sauce with the Passata, and the herbs just simmer for the time it takes to cut the veggies, then pour over and place the oven for 30 mins at 180c.
And enjoy with some crusty bread!