For the uttapam: I buy Saravana Bhavan's ready made dosa/idli/uttapam batter from Lulu Hypermarket. Just pour into a hot pan like a pancake and top with chopped onions, chopped green chilies, cilantro, ground coconut, and a few slices of tomatoes. Making dosa batter from scratch would be above my level of cooking skills, though I have been told it is very easy. I have used the boxed Gitz dosa mix before, but I don't recommend it.
For the sambhar: boil toor/arhar ki daal. When it is done, add in a medley of vegetables of your choice, plus some garlic, ginger, and onions chopped. To be true to a sambhar recipe, I recommend tomatoes, carrots, potatoes, eggplant, drumstick vegetable, pearl onions, green beans, and some type of pumpkin. (I buy a packet of pre-cut up mixed veggies called "sambhar vegetables" from Lulu Hypermarket) and cook them till tender, add in about a cup of tamarind water, add in sambhar masala to taste---about 2 tbs (I use Eastern Brand), salt, and a tempering of mustard seeds and dried red chilies, and curry leaves.
For the coconut chutney: in a blender blitz 1 cup fresh ground coconut flesh, 3 chopped green chilies, 1tsp ginger, and some water, and salt to taste, stir in lemon juice, temper with a few curry leaves, 2-3 dried red chilies, a pinch of mustard seeds, and a pinch of unsoaked uraad daal.