Preheat oven to 400 degrees F. Slice zucchini in 1/4-inch thick rounds. Place them in a bowl and toss with sea salt; allow to rest for 15 minutes.
Blot zucchini with a paper towel to remove excess moisture. Place on a baking sheet, drizzle with olive oil and season with pepper. Roast for 15 minutes, flipping halfway through. Remove from oven and allow to cool slightly.
In a small bowl, mix ricotta, minced garlic clove, oregano, basil and milk. Blend well until smooth.
Slice open rolls. Spread each with ricotta and layer with zucchini; close sandwich.
Shred lettuce and dice tomato. Place in a bowl and toss with dressing.