Tomatoes, aubergine, zucchini and bell peppers stuffed with red rice

My grandmother used to make this summer dish but i never got hold of the recipe. Later ,when I  tried to cook it myself,  I had to experiment; once I've made the stuffing with minced meat, following a mainland greek recipe and another time with pine nuts and raisins, according to the greek Asia-Minor tradition.

Today I have cooked the stuffed vegetables under the instructions of grandma Irene from Valmas tavern in Ios island, where I've spent most of my holiday this year. Irene's cooking style is simple, traditional and full of flavour.  I had the chance to taste many of Irene's dishes, the stuffed vegetables being one of my favourites; a light and refreshing meal, which makes use of a variety of summer products. The two things I have changed in the recipe are the rice, from rice pilau to red rice and I made a mustard and lemon juice marinade for the potatoes.

Ingredients

200ml olive oil
2 medium onions or 1 big one, grated
a bunch of parsley
2 Tbsp dried peppermint or some fresh one
1 aubergine
1 zucchini
2 bell peppers ( different colours)
2 beef tomatoes
2 potatoes
1 tbsp mustard dijon
1/2 lemon juice
1 tbsp of red rice for each vegetable ( in this case 6 tbsp)
salt and pepper

First I clean, peel and cut the potatoes into wedges. I put them in a bowl to rest with a tbsp of mustard and the juice of half a lemon. Then I will clean the tomatoes, aubergine, peppers and zucchini,  cut their tops and scoop out the pulp into a blender with the parsley and the peppermint. I will add the grated onion and half of the olive oil. After I have positioned the vegetables into the baking tray, i will start filling them with the mixture and a spoon of red rice to each. Whatever space is left empty in the tray, it will be covered with the potatoes. On top I will pour the rest of the olive oil. I put the tray in a preheated oven and leave it to cook for 1 hour and a half.