I like using tajine. It is the closest thing I have to a slow cooker. Both the bottom and top sections are made of glazed clay, and hence, the need for a heat diffuser for my gas top cooking range.
Almost anything can be cooked in a tajine. I go through the fridge and see what is in there that is about a week old; the single eggplant, quarter pumpkin, one miserable potato and a lonely carrot. Great!
Cut eggplant and potato into thick slices, and the rest cut into chunks. Add a packet of tempeh (or hard tofu), also cut into chunks. Chopped about 3 to 4 ripe tomatoes (or half a canned of diced tomatoes), and add 3 tablespoons of ras-el-hanout (available form middle eastern groceries, or make your own), a dash of cayenne, salt and pepper to taste.
Grease the bottom of the tajine with 2 to 3 tablespoons of olive oil, place some sliced onions and chopped garlic and pile cut vegetables into a little pyramid, pour the tomato mixture on top, cover the tajine with its cavernous cone-shaped top part and leave to cook very slowly over very low flame for about 90 minutes.
That is how simple it is.
You can also find tajine with non-stick Teflon bottom section, while others are made of cast iron. I have never used non-clay tajine so I can’t comment on the performance and taste. Dishes cooked in a clay utensil acquire a special taste and fragrance, which you don’t get from other materials.