1 lb. small Brussels sprouts, trimmed and halved (quartered if large)
8 to 10 ounces mixed baby lettuces
1 tart-sweet apple (such as Honeycrisp or Pink Lady), quartered and thinly sliced
1/3 c. sliced or slivered almonds, toasted
2 to 3 ounces Asiago cheese, shaved
1 tbsp. chopped fresh chives
1. Make vinaigrette: Place orange juice, vinegar, lemon juice, maple syrup, and mustard in a blender. Blend until well combined, 10 to 15 seconds. With blender running, gradually add oil until emulsified, 45 to 60 seconds. Season with salt and pepper. Store in a jar in refrigerator up to 1 week.
2. Make salad: Line a plate with paper towels. Heat oil in a large cast-iron skillet over medium-high heat until very hot but not smoking, 1 minute. Carefully add Brussels sprouts, cut sides down, and cook, without turning, until crisp-tender and golden brown, 3 to 4 minutes. Transfer to a paper towel–lined plate with a slotted spoon. Season with salt.
3. Toss together lettuces, apple, Brussels sprouts, and 1/4 cup vinaigrette in a serving bowl. Top with almonds, cheese, and chives. Serve immediately with remaining vinaigrette alongside.