Put the tomatoes in a baking dish that’s just large enough to accommodate them all in one layer. Add the oil, cumin, sugar, garlic, thyme, oregano sprigs, lemon strips, half a teaspoon of salt and a good grind of pepper. Roast for 20 minutes, until the tomatoes are beginning to blister and the liquid is bubbling, then turn the oven to the grill setting and grill for six to eight minutes, until the tomatoes start to blacken on top. Or use a blowtorch like I sometimes do. Because how often do you get the chance to use a blowtorch? If you don't own one go and buy one because according to Julia Child every woman should have a blowtorch.