Spencer Rubin is all about the sandwich.

“I think sandwiches are underestimated in terms of the amount of work and complexity of what goes into making one,” said the founder of grilled cheese concept Melt Shop.

Rubin continues the ode to the sandwich with Make Sandwich (135 Fourth Ave.), his month-old Union Square eatery that features modern, gourmet takes on deli classics. For instance, its sausage, egg and cheese is made with maple-ginger breakfast sausage, pimento and cheddar cheeses, an organic egg and chile ketchup, all on a brioche bun.

One of the most popular menu items so far is Make Sandwich’s take on the steak sandwich, which was the result of many, many trials.

“We tried all different cuts of beef, roasted them, grilled them — we were trying to come up with the perfect steak sandwich,” Rubin said. “After a month of trying, 40 or 50 different steak sandwiches, we realized we were really overcomplicating it.”

The winning sandwich that’s on Make Sandwich’s menu features just three ingredients: Pat LaFrieda all-natural, antibiotic tri-tip that’s seared and roasted to medium rare and sliced to order, topped with a housemade salsa verde and served on a fresh-baked baguette.

“Everything starts out with the bread — getting really good, high-quality bread is the most important first step,” said Rubin, who gets all of Make Sandwich’s baguettes, brioches, ciabattas and sub rolls from Pain d’Avignon.

For the beef, Rubin likes tri-tip because it’s not very fatty, compared to a cut like rib eye.

“For this sandwich, we wanted something a little bit leaner but also had that steak flavor profile,” said Rubin. “The tri-tip married the two worlds perfectly.”

The salsa verde adds a brightness and acidity. The end result makes for “the perfect sandwich experience,” Rubin said.

The chef was willing to part with his sandwich-making secrets, with a recipe for Make Sandwich’s steak and salsa verde sandwich in time for Sunday’s big game. It makes for the rare Super Bowl food you won’t feel too guilty about eating.

“A lot of steak sandwiches are often very heavy; the beauty of our steak sandwich is it’s really consumable and something you can eat quite often,” Rubin said. “There’s not a ton of cheese on it, it’s not overcooked, heavy meat. It’s this beautifully cooked meat with a bright salsa verde on it.”

If you’re planning to make it at home, most butcher shops should have tri-tip, though you can sub with sirloin if you can’t find it, Rubin said. As for sides, you can’t go wrong with potato chips and pickles.

“For sandwiches, I love chips and pickles — kind of an old-school combination,” Rubin said. “At Make, we make all our pickles in-house. We don’t make our own potato chips — that’s the one thing we don’t make.”