Warm the vegetable broth over low heat in a pot.
Cut garlic into small pieces. Warm olive oil over low heat and gently sauté garlic until fragrance comes out.
Add the clams and white wine to the pan. Cover and cook over medium-high heat for 3-4 minutes until shells open. Remove the clams and set aside, keeping the liquid in the pan.
Put rice to the pan over low-medium heat. Stir throughly until coated with the reserved liquid from the clams. When the liquid is well absorbed, add sliced zucchini, diced tomatoes and 1 cup of warmed vegetable broth. Add 1 cup of broth at a time and constantly stir until each portion of broth is absorbed before adding the next portion. Repeat this process (around 3-4 times) until rice is cooked tender or al dente.
Add salt, pepper and butter for seasoning. Put the clams back to the pan and mix until sufficiently heated. Sprinkle dill (or parsley) on the top to give it a nice colour.