During the summer months, there is not better way to do justice to ripe cherry tomatoes than by slow roasting them. This highlights their natural sweetness and caramelizes their fresh juice. During off season, this technique transforms ordinary supermarket varieties into a rich tasting, sweet tomato "sauce". Spaghetti and red sauce never looked or tasted so good. Source unknown
Preheat oven to 250. Heat the 1/4 cup oil in large skillet over medium heat. Add onion and garlic and cook, stirring occasionally, til tender, 5 minutes. Remove from heat. Add whole Basil leaves and red pepper flakes. Stir well.
toss tomatoes with 1 tsp. of salt and the sugar and put in roasting pan. Pan should be large enough to hold them in a single layer. If they won't fit, use another roasting pan-and more oil. Spoon onion mixture over tomatoes. Add enough oi to come halfway up the tomatoes.roast til tomatoes are tender but not falling apart, 3 hours. Stir once, gently, during roasting. You can roast the tomatoes 6 hours ahead.
Bring large pot of water with remaining 2 tsp. salt to boil. Add spaghetti and stir contently til water returns to boil. Cook til pasta is al dente, about 7 minutes
Meanwhile, heat tomatoes and onion in large pan over low heat. When pasta is done, drain and transfer to pan with tomatoes. Add arugula. Toss well. Add basil ribbons and toss again. Serve at once in warm shallow bowls with Parmesan sprinkled over the top.
It's best to wait to cut the basil into thin ribbons til just before you're ready to add it to the sauce. otherwise, it will darken. If you haven't bought a jar of crushed red pepper flakes in a while, add an extra pinch. The heat mellows over time. Since cherry and grape tomatoes vary quite a bit in size,the better way to measure is by volume. Figure 2 heaping pints of tomatoes. You can substitute baby spinach if you can't find good tasting arugula. Ideally, the roasting pan should accommodate the tomatoes in a relatively snug single layer. If they are spread too far apart, you'll need to add too much oil to the pan to come halfway up the sides of tomatoes.Thinly slicing is better than chopping for leaves such as basil, arugula and lettuce because it's less likely to bruise them. Begin by separating the leaves from stems or from the head in the case of lettuce. Wash and dry them thoroughly. Then stack the leaves neatly and roll up pile tightly...imagine rolling up a big fat cigar. Using a large chef's knife, slice across roll to make fine or coarse strips. This technique creates what French chefs refer to as a chiffonade.