Preheat the oven to 450°F. Halve the potatoes lengthwise. On a lined sheet pan, toss the potatoes with a drizzle of oil; season with ½ the spice blend and S&P. Arrange in a single, even layer and roast in the oven, 20 to 25 minutes, until browned and tender when pierced with a fork. Remove from the oven and set aside in a warm spot.

While the potatoes roast, separate the lettuce leaves, discarding the root end, and tear into bite-sized pieces. Peel and mince the shallot. Pick the tarragon leaves off the stems.

In a large pan (nonstick if possible), heat a drizzle of oil on medium-high. Pat the filets mignon* dry with paper towel; season with ½ the remaining spice blend and S&P. Add to the pan and cook, 2 to 3 minutes per side, until cooked as desired. Transfer the cooked filets to a cutting board and let rest for 5 minutes before thinly slicing against the grain.

Heat the same pan on medium (add a drizzle of oil if the pan seems dry). Add the shallots and cook, stirring frequently, 2 to 3 minutes until fragrant. Add up to ½ the tarragon (to taste) and ½ the vinegar. Cook, 1 to 2 minutes, until most of the vinegar has reduced. Transfer to a bowl. Add the sour cream, mayonnaise, as much mustard as you’d like (starting with ½) and 1 tbsp of water (double for 4 portions). Stir well to combine; season with S&P to taste.

In the same pan, heat a drizzle of oil on medium. Pat the shrimp dry with paper towel; season with the remaining spice blend and S&P. Add the shrimp* to the pan in a single, even layer and cook, 2 to 3 minutes per side, until opaque and cooked through. Transfer to a plate and set aside in a warm spot.

In a large bowl, add the remaining vinegar and 3 tbsp of olive oil (double for 4 portions); season with S&P to taste. Add the lettuce and toss to combine. Divide the roasted potatoes, filets mignon and shrimp between your plates. Top the filets with as much of the béarnaise sauce as you’d like; garnish with as much remaining tarragon as you’d like. Serve the salad on the side. Bon appétit!