To prepare pickled onions, place onions in a bowl. Add boiling water to just cover onion; let stand 2 minutes. Drain; return to bowl. Combine juice and next 6 ingredients (juice through dash of red pepper); add to onions, tossing well. Cool to room temperature. Cover and chill overnight.
To prepare the potatoes, preheat the oven to 400°.
Combine 2 teaspoons thyme and next 4 ingredients (2 teaspoons thyme through 2 garlic cloves) in a roasting pan coated with cooking spray. Add potatoes; toss well to combine. Add broth to pan. Bake at 400°, uncovered, 1 hour and 15 minutes or until potatoes are brown and liquid has almost evaporated, stirring once.
To prepare beef, heat oil in a saucepan over medium heat. Add shallots and 1 garlic clove, and cook 5 minutes or until tender, stirring frequently. Stir in 1 teaspoon juniper, 1 teaspoon thyme, and dash of red pepper; cook 1 minute. Remove from heat; stir in wine and 1/2 teaspoon black pepper. Cool to room temperature. Rub shallot mixture over both sides of steak. Cover and chill 2 hours.
Prepare grill or grill pan.
Sprinkle steak with 1/4 teaspoon salt, and lightly coat with cooking spray. Cook steak for 5 minutes on each side or until desired degree of doneness. Remove from heat; let stand 5 minutes. Cut steak diagonally across grain into thin slices. Serve steak with onions and potatoes.