Diana Henry's salmon tartare with avocado on rye bread

Name: Diana Henry's salmon tartare recipe with avocado on rye bread
Yield: Serves 2
Ingredients: 150g salmon fillet, skinned; 1 small shallot, very finely chopped; 1tbsp dill fronds, finely chopped; 1/2tbsp lemon juice; 2tbsp extra-virgin olive oil (fruity rather than grassy); 2 slices rye bread; 1 large, ripe avocado; Lemon juice, to taste; Avocado oil, to taste; 2 crisp, fresh radishes, cut into matchsticks