Roast bell peppers and jalapeño over the flame or in a preheated 425ºF/220ºC oven for 40 minutes (grilling vegetables and fruits does not create carcinogens). Once you've roasted your peppers, you will need to steam them. This process will help you peel the tough skin from them more easily. Place the roasted peppers in a freezer bag or pastry bowl covered with plastic wrap and steam for 15 minutes then peel using paper towels. Remove and discard skin, stems, membranes and seeds. Chopped peppers and set aside. For a mild ratatouille, use half of the seeded and chopped jalapeño. Meanwhile chop onion, celery, carrots and mince garlic. Heat up a large skillet, add butter and olive oil and sauté the mirepoix; onion, celery and carrots for 10 minutes on medium high heat. Add garlic and the chopped peppers, tomatoes, olives, 2 thyme sprigs, herbs de Provence, salt and pepper. Cook the mixture for 40 minutes; uncovered or until all veggies are cooked through and steams is out. Discard thyme, and gently puree the ratatouille mixture in a food processor with the basil; let cool completely.
Place cheese shortbread bars on plates (Look up for the recipe). Fill pastry bag with some of chilled ratatouille mixture and pipe it out. Square out edges using two offset spatula. Garnish with small spheres of sour cream, small cherry tomatoes halves, some toasted hazelnuts, and basil leaves. Bon appétit!