Lemony Lentil Salad with Salmon

1/3 cup(s) chopped fresh dill

2 teaspoon(s) Dijon mustard

1/4 teaspoon(s) salt , or to taste

Freshly ground pepper , to taste

1/3 cup(s) extra-virgin olive oil

1 medium red bell pepper , seeded and diced

1 cup(s) diced seedless cucumber

1/2 cup(s) finely chopped red onion

2 can(s) lentils , rinsed, or 3 cups cooked brown or green lentils

2 can(s) salmon , drained and flaked, or 1 1/2 cups flaked cooked