In a large pot over medium heat, pour in 4 cups of dashi or broth. Add 2 minced garlic cloves and 1 tablespoon of freshly grated ginger. Bring to a gentle simmer for about 10 minutes.

While the broth simmers, bring another pot of salted water to a boil. Add udon noodles and cook for about 8-10 minutes until tender. Drain and rinse with cold water.

Return to the simmering broth, gently add 1 cup of vegetables and 1 cup of cubed tofu or chicken. Allow to simmer for another 5-7 minutes.

Stir in 2-3 tablespoons of soy sauce to adjust the broth's seasoning. Taste and adjust as necessary.

Add the cooked udon noodles to the pot. Gently stir to combine and soak up the flavors for about 2 minutes.

Ladle the soup into bowls, garnishing with sliced green onions and optional sesame seeds or nori strips. Serve immediately.